It's interesting that you feel that you are stuck in the mindset of a sixteen year-old at times, because my ex-fiance told me something similar before I was asked to leave.
It is true that I think that when I got into drinking, I was acting incredibly immaturely at an age more advanced than where you are now. I want my relief, and I want it now is what I was shooting toward when I was drinking, and it was getting me nowhere faster all the time. I don't know if I'm any more mature now than what I was at the time she pointed it out to me, but I am trying to do real things to act that way.
I say act that way, because there are a number of things in my past that could have contributed to my being emotionally stuck in my life, but I'm doing the action part now as my focus and will try to figure out some of the other parts as I go. Right now it's working for me.
It is a good insight that I hope that you can carry further into your new pattern of not drinking and for feeling that you will be making further progress on your other problems.