No one asked, but I'm going to weigh in on this. First off, despite being a 'male' (right, guilty as charged), I'm not (could be deluding myself) biased in his favour. Before I blithely ramble on any further, going to warn you that I am not prone to delicacy. More like a bull in a china shop. If I tread on anyone's toes, I honestly do apologize first and foremost. Second, if you knew me first hand, then it would be obvious that I in no way shape or form could ever hope to be a 'couples therapist'. In many ways, I find people and relationships a puzzle. No great insights here. But I was born intrigued by puzzles, so I have watched and... possibly, supposedly, may have learned a thing or two over the decades.
Having thus forewarned you... Here goes. You are in the midst of a life-changing illness. That won't go away. It does have an impact. Of all of the critical things in your life, you have to put your health first. Boyfriends come N go (and, no, there wasn't an underlying message in those bon mots, I swear), but you only get one life. Do the math! Understand the undeniable principal. If you do have to sacrifice one or the other, give the b/f the heave. He just isn't worth sacrificing your life/health for. Sorry if that comes across as a short and hard statement; a black N white oversimplification, or an unfeeling assessment but... (BIG BUT).. self preservation has to come first. You have no options that otherwise make sense... you have no choice in your illness, can't wish it away. He has a choice... to accept the 'new' reality, to learn to cope with your crohns.
He MAY not make the choice you want him to. Pardon me for saying so, but if he doesn't, then it's definitely for the best. You need someone you can depend on. If you allow yourself to rely on him now, given his shakey behaviour, what may become of you if your situation gets critical, and you REALLY need his help?
Food for thought. Why people love who they love, who's to know. Love can be a gift, or a curse, or a mixture. Think you have been blinded by your love to his lesser points. Like, for instance, you've told us he is selfish.. common flaw. But how/why do you know about how often/frequently he had sex with his prior g/f's? Somehow, I don't picture this being of keen interest to you. I suppose in this day of 'uncurable' sexually related diseases, one has a right to know 'how' many prior sex partners one may have known.... at least a rough idea of total. BUT frequency? You said he made you feel inadequate. If this is typical of his behaviour, then you've called it right. He is deliberately making you feel worse.
Let's do a little what if scenario. now, he's a boyfriend, manipulative, unreliable and selfish, making nitely demands on you despite your illness. How do you see him as a possible 'parent'? I know, no one mentioned that, but lets pretend you are looking at a possible future, one of many. Can you picture entrusting your children to his 'sole' care (remember, you have an uncurable illness, OK)?
If you can't picture him stepping up and being a loving, supportive father, how can you picture him being a loving, supportive partner? Oversimplified, YES! It's a case of sometimes life doesn't permit you to weigh yourself down with all of the extra nuances... Now, for those who think I'm being too judgement, that I am being too cut N dried, that he possibly has all of these other good points, or that I've painted us males in general too dark... I'm not anti male. Neither am I blind to the fact that both our genders have our less than noble sides to them.
for instance, the bit about some men judging relationships by sex. Think it is a wee bit more common than that. Distinction is that most of us don't just weigh the sex... it is an important bit... I also believe (and who am I to say) that lots of males either develop, or believe, that the 'health' of their relationship is only truly percieved from the frequency/quality of the sex. I didn't claim this was in any way a 'valid' marker, just a bit of common male 'folk lore'. Whether women can accept that or not, relate to that or not, or even perhaps admit they know it and occasionally exploit it.. hey, let's not get into that debate. I've just never met a man in a relationship who didn't use their sex life as a built in gauge of their relationship. No sex = what did I do wrong, or what didn't I do, or whats' wrong now.. or she's not interested in me anymore, or maybe theres someone else... the list goes on and on. And notice, it's mostly 'male' centric thinking. A case of 'I, I, I'... like your world revolves around us. Pretty shallow thinking that we can be prone to. Sex urges typically are shallow. Survival of species thing. I am not saying that men alone can be shallow. From how you write about way the other 'girls' greet him, seems your b/f is a fairly attractive fellow to the gals.
Is that what initally drew you to him? Is that why you've stayed as long as you have? Is that your key reluctance to ending this? Only you can answer that. I'm not singling you out.. Men/women, we respond to visually attractive people, its one of natures ways. Even if it wasn't there via nature, our culture nurtures it.
So, I'm not judging you, nor your life choices... As a matter of fact, I think you've already decided, deep down inside, what you have to do. And you know it. But it's a painful prospect, and it just doesn't seem fair to have to face that extra pain when one is already fighting the painful reality of a life with this disease. I think you were just talking out loud, to yourself more or less, to see if there was any support, to muster the courage. so, take it from an old man who is so unthinking, unfeeling, so 'shallow' to just call it (black N white) as he sees it. It seems that your current boyfriend is a shallow, uncaring, selfish, unreliable bit of eye candy that you had a sweet tooth for... but now you have to watch what you eat. And he should be stricken from your diet. you need something just a bit more substantial. No matter how appetizing they may appear, one can't live on sweets. Course, the choice is yours... But I feel that you've made it already.
If I can say anything (after all of that tripe above) that might make you feel just a little better... Picture it this way. Imagine a silly gal or two, hearing that you gave the b/f his 'wise up or get lost orders', thinking how silly of you to do that.
But, other, wiser women saying 'How smart N heroic of her to give him the axe'
Hey, what do I know? Huh. If you've read this far, and seen that I've the sheer gall, the nerve, to advise you, to lay out your life choices in simple black/white, I hope you realize that I'm just a looney old man who wishes you all the best, OK