Like Mallard said and a few others. If she is at 95% and breaking even, something ain't right in the business plan.
I know 4 yrs ago you may have not thought you were going to be in this situation but if you were to go after a 4 year degree you could have had it by now. Yes that might involve getting some debt but ideally the degree would pay itself off. I know you said you hated going to school but do you hate more not being able to provide for the family?
I know you have a lot of feedback giving you a very ideal and 'romantic' if you will, idea of sticking with the cake business. I am going to go out on a ledge and say no. Maybe she can continue to develop her name part time, as more of a hobby than a business. At this point I would argue she has to get a job, specifically a job with benefits. The #1 reason for bankruptcy is health related costs and debt. Obviously you have some issues and you said she is starting to develop stuff. Considering 'her body' (not trying to be perverted) is the most valuable asset to your family at this point, as it will enable her to work and provide, this is the #1 priority. Continue the business on the side, maybe selecting the higher profile jobs with better exposure.
I'm not exactly sure what kind of pain and disability you are in, but would amputation eliminate the pain? Would it allow you to get back to work? You have to stop and consider extended use of pain medication can't be doing your body good. Try to think of your situation and your body objectively. If you had a car that was costing you more money than it was helping or was worth, would you get rid of it? There are so many options now for amputees to live a relatively normal life, it might be a very real option to help you.
Keep your head up.