I understand that the idea of eating any amount of food to create matter you're going to have to expel on a daily basis and risk worsening the situation is, quite honestly, hell. The amount of mental torture this situation wreaks on a person (not to mention all the terrible physical aspects) is just so hard to deal with, let alone expect other people to understand... it can feel like you're just alone in it.
But I want to encourage you to get plenty of fiber... whatever you do eat, please make sure that there is sufficient fiber in it. If you can't work your vegetables/greens into every meal, please use a fiber supplement. Stay hydrated and get your fiber. It will make things so much easier. You can't run yourself ragged with your daily demands, with physical discomfort, and with mental suffering, and not eat enough too. It will burn you out, and make things worse.
Food is not an enemy, even though it may seem logical to feel that it is. It's only an enemy if there is not sufficient fiber in it, and if you don't drink enough water to move it all through your system.
I'm glad you are using a stool. The biggest lie we all live with on a daily basis, that perhaps many people don't suffer consequence for, is SITTING to do our #2 business. It is completely unnatural. We are meant to squat when we relieve ourselves.
I determined that using a stool to elevate the feet was not enough. I have been using the squatting method ever since. In the privacy of your own bathroom where no one else sees you... who cares what you have to do in order to make life easier for yourself? Line a bedpan or some other type of easily sanitized receptacle with toilet paper, squat and do your business. Empty that in the toilet, and sanitize.
I recommend perineal cleansing bottles to clean yourself when you are done rather than any type of wiping, which can cause further damage. Cleansing bottles are highly effective and also quite soothing. Even when there is a new injury and the process stings... just know that you are getting yourself as clean as it can get, and in the process, avoiding the possibility of infection etc.
Salt those baths with epsom salts or Dead Sea salt, just any type which is most cost-effective for you. The salts are soothing, purifying, and really, they are medicinal.
It gets easier. You would be surprised what you can get used to, and what can become second-nature to you.
You're armed with knowledge and experience now... it will get better. Being able to do this, to get through this, and to minimize damage in the future will help you lead a better and stronger life. You will be okay.