shyness & self consiousness

I am struggling through life because of my shyness. I was raised in a strict catholic family and not allowed to have friends over or go places. I am now in my early 30's and struggling with few friends and I sabotage every wonderful career opportunity that's come my way....which have been a lot. I panic and then pass the opportunity to someone else. The problem I've encountered recently over and over again is people when I meet them saying to me, "are you alright, you look like you're going to have a breakdown, or relax, and they pick up on my problem. I don't know what's happening, but I used to be able to disguise it more and now I'm becoming even more fearful of meeting new people etc. because of all of these recent comments. I just want to hide more. They seem to be happening with almost everyone. I recently put on some weight so I attribute this to that...that my self image has gone down. To sum it up, I am so tired of holding myself back in life this way. It is so painful to know that I am living with this problem and I want to change. What do I do to change this? Any advice as to what's happening with me and I attribute my shyness to the environment I grew up in, am I correct? (although my brothers are not this way) Please help!