Hi sexyk and welcome to the forum.
alot of people here have experianced your situation to a greater or a lesser extent. it is truly horrible to be shunned by those you love, just remember that they are probably very scared of repurcussions should they have contact with you because "the jw religion is at worst a cult and at best a high control group" (that thought is ripped off from a post on JWD that I read, sorry to the author, i don't know who you are to give you credit!). it can get better with time. let them know that your door is always open and that you love them and will always be willing to speak to them, if they won't answer your calls, try an e-mail or letter, they may read those.
i personally know what it is like to feel that you cannot trust anyone, your trust has been abused by the borg and you have been taught/brainwashed into thinking that "worldly" people are untrustworthy too, so no wonder you feel lost.
just remember that things can get better, people here have survived and you can survive too. Talk to your gf - she may not like you being possesive but if she can understand why then you will be able to work through it. i spend ages pushing my partner away but he could see that there were reasons why and just kept on showing how worthy of my trust he is.