hello and welcome...i think your boyfriend is feeling vulnerable..being bullied is never easy to overcome and you mention his childhood wasn,t that great.
he has obviously lost a lot of self confidence and when this happens you do start to see things in a whole new light.
I can relate to his fear of people and what he shall feel is heart rate increasing to palpitation. A heavy gut feeling in his stomach and fear of confrontation.
he is protecting himself from being hurt and i would advise he has to seek councelling to talk about his past and learn to deal with his demons..
this could grind him down if gets out of control and eventually he shall just not want to go anywhere and stay indoors..he is making his home his comfort zone where he feels safe.
i had too push myself also to do this and feel better for seeking help with a councillor..this is a horrible feeling to have everyday and would not say its paranoia its a fear of what may or could happen.
im so glad he has your support and together he can with help get this time of his life under control and not let his past make life a misery. I feel great now and wish had done it sooner so with great support and understanding your boyfriend should start to get control back..
wishing you both the very best and keep in touch.