One of the purposes of relationship is to heal our past.  This means that subconsciously we will create ‘drama’ in the present in which to replay and recreate hurts of the past so that we might heal them. That you have done the same thing with past boyfriends certainly indicates that this process is in play.

The first step in healing this issue is noticing and naming the issue. The next step is to take ownership of it. This trust issue is your issue and is not about your partner.  This is about you.

You might find talking the issue out with a third party not involved on impacted by your relationship helpful.  it might be enough to stop insecurity just noticing that your doing it however most people need to understand where issue of insecurity originated from so that they can better deal with it the present.  The key is making the problem conscious so that you no longer reacting to the triggers and instead responding.