For me it was that I didn’t have the information I needed to process what I was feeling and deal with what was wrong. I didn’t have the language to even describe that something was wrong.
I know many others in my situation that ended up with worse coping mechanisms in the same circumstance. Heavy drinking and drug use is common in the community.
That said, addictions can be physical. There’s a reason you have to ween people off of certain substances because withdrawal can kill them.