I see you are in good hands with vets lining up to guide you. You have supported many here, so make the most of the guidance offered to you.
I too am an intervert. I am not sure we can really change our nature but we can stop it dictating actions that are harmful to us. We can do more stuff. We can go towards people. We can be intimate in friendships and R.
Being introvert is not an issue. The behaviours that can cause are. Identify those behaviours and work on them. Not all behaviours need to be eliminated either. They can be reduced, modified, changed, controlled, etc.
R 25 years M 14 years S11 & S13 Working on it alone since Oct 2014 M in trouble a lot earlier (~2 years) Feb 2016. 1st R chat in a yr. Next R chat Aug'17 Still together