costello - I am glad to hear you say you're considering another arrangement. Right now it seems that neither one of you is doing very well, and that should be changed. It's perfectly clear how much you love and care for your son, but love can't make him better. What it can do is completely exhaust you, and leave you both full of resentment for the other.
There really are lots of options and levels of either independence, or professional care available depending on what your son needs. It could be the thing you both need to improve your relationship, and help him get better.