You might be looking at it with too much of an "all or nothing" attitude. You don't have to get a permanent full time job that would be overwhelming and lead to a breakdown. Maybe you could work for a little while when you were going through a good period. Maybe you could do a few hours, or volunteering, and see how it goes. It doesn't have to be forever. I have found that sometimes it is easier to cope with sensory things or anxiety or whatever when other aspects of life are more sorted. So if something like smells is putting you off working with animals, maybe you would find that if you were volunteering for only a few hours a week, without the stress of being relied on/having to be there, having pressure to perform, having the stres of full time work, etc, then you might be able to develop the strategies you need to cope with the smells when it's one of only a few sources of stress - rather than thinking you need to take a stressful full time job with social stresses and performance pressures and organisation problems etc and then cope with smells on top of that, which might be impossible.
Or for example, I can cope with certain aspects of work anxiety better when I have reduced social commitments, or have more work at home; having more financial stability means less anxiety about things going wrong in the areas that are difficult, because my life doesn't depend quite as heavily on having to do well in those areas. So things that seem impossible in some situations might not always be like that in others. And some of it is incredibly hard to do and very uncomfortable/painful - but with strategies, some of it can be managed, as long as other things are in place. I think many people do have to endure some things that are very uncomfortable as part of their jobs, but they are able to do it because they don't have so many other challenges in all the other areas of their life - you have loads of difficult things to manage at the same time, which makes all of them feel impossible. But if you could reduce some of the stress in other areas, then you might find that you are more able to deal with one challenge at a time. Not that it will be easy or that you'll find it comfortable or painless or anything, I think that's unrealistic for anyone, but maybe you can get to the point where you can tolerate that smaller amount of anxiety.
You could possibly find that even just small bits of work or volunteering, with no pressure to make them 'successful', might give you motivation, structure etc in a way that a full time job wouldn't. So even selling your crafts online - if there is competition and you don't do as well as you wanted, it doesn't mean you won't get something out of doing it. Or if you tried it and had to give up, that's OK too; you don't have to get to the point where it's a breakdown and affecting your health - you could see how it goes, see what strategies might make you more able to cope with the difficult bits, see if you can ease into things enough to cope with the health side of it, and keep things on the right side of manageable.