Welcome back @Vision 
It’s hard when you grow through PTSD, autism, and cancer. Each of those is complex, and together they can amplify each other.
There is always a reason to use. (Edit to add: what I mean is, there’s always a reason, but we have to choose not to, and we have to do what we need to do, to not use. It’s that simple.) It’s true that PTSD is a difficult hurdle to pass - but it is passable. It is something you can work through. And it is possible to live and feel one day at a time, if you keep asking for help and surround yourself with the supports you need.
It is possible to grow through the other needs you have too. One key is to resist that urge to isolate, and instead to push yourself to reach out for help. You don’t have to become the centre of attention, that’s not what I mean; but you do have to resist that voice telling you it’s not worth reaching out. Today is a start - keep it up
Personally I find it helpful to check in here, as many times as I need to:
Checking in daily to maintain focus #40
It’s also helpful to get the medical and psych support you need. It’s no different from a diabetic needing insulin to live. It’s not good or bad, it just is. Reach out to a doctor, seek support, reach out to community support organizations, connect - connections are the key to recovery.
You deserve a life where you feel like you’re moving forward. You can do it. One step at a time 