Personally, I've not found talk-therapies helpful at all. I think because I have real problems, whereas some people seem to be depressed not because their life is terrible but because they think irrationally and so a therapist can point out where their thinking is distorted. Because I've had a lot of really bad things happen to me, there's no way I can logically be happy with my situation and my past; there's no way a therapist can talk me into being content with things unless they were able to get me believing in delusions. (Though I have seen mental health professionals who seemed convinced they could.) I don't think I have any mental illness so much as the only real way for me to feel about my life is anxious and unhappy. I like to be practical and try and fix things in my life, just talking about things doesn't change the problem, and so doesn't make me feel better.
However, I have found medication helps my mental state and emotions more than I ever thought it would. I've heard people say that anti-depressants and similar medications just make them numb and stop them feeling anything, good or bad. But with the one I take I still feel emotions, including still feeling unhappiness. But on the medication I can cope with my unhappiness, which enables me accept the bad things that have happened to me. It's really hard to explain what I mean - when I read about the medication it seems my experiences are not what typically happens to people taking it.
So my advice would be to first consider whether your situation warrants the extent of depression you are feeling. And although only you can decide this, I would suggest that if having Crohn's is the only reason you came close to considering taking your own life, it's possible you are more depressed than you need to be. I don't mean this to sound flippant - your depression is no less real even if the extent of it isn't completely rational.
Because Crohn's is a real problem, anything you can do to reduce your symptoms should help to make you feel better mentally. Finding the right doctor, trying different meds, finding ways to adjust your life so that you can manage your Crohn's more easily - anything you can do about the physical illness will help put your mind in a better place too.
But because there are a lot of people with Crohn's who don't feel as depressed as you, a therapist may be able to help you see whether you feel worse than you need to be. For example, if you are depressed because you expect you'll be spending a lot of time in hospitals, a therapist may be able to help you concentrate more on the times in the future where you won't be in hospital, or perhaps help you see why being in hospital may not be quite as bad as you imagine.
As I said, my experience is that medication can help a great deal, although there are so many different medications and they can affect people so differently, it's impossible to say whether you would benefit, the only way to find out is to try. It certainly doesn't have to be covering up the problem. Medication helps me deal with problems and the emotions they cause, it helps me see and feel with more clarity rather than blocking reality out.