Trust... I just can't seem to get enough

Somethings just haven't been left in 2010. Something I wish could have been left in 2010 and others that have been around since '08 no longer are.
I lost a friend to my temper start of this week. Temper caused by something I have told my self would never cause anything like this and if it did not to be spoke of. I held on to something that gave me the power and justification to act an ass or for why I acted like a crazy woman by bursts of anger years ago and I gave it all way in less than 5 minutes let it consume me then end my friendship one thats has been around longer than my relationship because I was having issues trusting the person I am dating.
I would ask what you think about why it is I can't ever believe what I hear from those that say the love and care about me? I say its because those that used caring and loving as a glue to stay in my life have done nothing but bring me down and lie to my face so why why should this time be any different so I thought if he loves. has me and is telling me that its the truth I thought so could some one else that says they cared for me or loved me before this one came along.
I don't seem to let go to be able to trust that you will leave to do your thing and not be doing something that would disturb my happiness because I am always getting the worst end of the rope/stick what ever you want to call it.