i have a 14 year old and a single parent, I have walked your shoes and its hard rejoice in the positive . My advice to you is let the system help you, get plugged in. With a diagnosis you should beable to get doors open for your son. It may be a fight and time consuming but will benefit you much later on. So Ask god to help you open the right doors for you. School should help, but often times they do a good job of pushing the blame on you, Keep your head up, Keep Asking because the right doors will open, Ask for a mental health case worker, get PCA's, respite, Get some help for you- Remeber god only gives you what you can handle. So dont think you cant. Find time some how to replenish your batteries, nature, walk or whatever.
I know how you feel- there has been nights I used to cry myself to sleep.
Get the right supports. Hope this has helped you a little- God Bless You