I have a few pets - a cat (obviously, ha ha), a hedgehog, a couple of gerbils, and yes, I have a dog. I've had my cat for about 8 years now and I am really more of a cat person than a dog person. I like that cats are so low maintenance, just give 'em food and clean their litter box, toss a little catnip and toys their way and they're fine. I had some concerns about getting a dog, like what if I get too sick to walk it or what if it needs more activity and attention than I can provide? But I found a dog in December that I couldn't say no to, a 2 year-old corgi who needed a new home as her former owners couldn't keep her any longer. And she's been great. My health has been improving although there are still some days when I'm feeling too exhausted to walk her, but she seems to understand. She's not a super high energy dog so that helps, and I'm glad I didn't get a puppy. A young adult dog like mine is pretty ideal - some energy, but not tons, and she will sleep all night and into the next day if I let her. She can entertain herself with bones or toys for hours but she'll also play with me if I'm feeling up to it.
If you're not sure if a dog is right for you, I suggest you consider other pets. My cat seems to know when I'm not feeling well and she will sit right near me, if not on me, and she'll even follow me into the bathroom. If you're dead set on getting a dog, do some research into various breeds to find one that sounds like a good fit for you. You could even foster a dog through your local animal shelter if you're not sure and want to take a dog for a test run before making up your mind. My parents are considering fostering a cat so I know it's an option, I think the Humane Society has foster programs and other shelters probably do too. Good luck with whatever you decide to do!