I may become a single mom, howdo you do it?

I have been with my one and only partner for 16 years and now after many hard years and good years and a 3 year old my husband recently said he is thinking of leaving if I don't get better. His reasons would be valid but I litter don't know how to live without him, especially as a parent. I don't make much money, I can't drive to to epilepsy, and I have no friends/support, and my family will probably be out of the picture some. They are very toxic. I have already been suicidal and am really only here for my boy but I feel like there is no way forward if he leaves. How do you guys do it? Advice please.