Really Bad Anxiety Moment.

So lately I've had a big spike when it comes to my anxiety. I've almost broken down in public twice and it gets really bad when I'm with my boyfriend and I start to get in my head and think he is going to turn out like the rest and I just keep thinking and thinking making unrealistic situations up in my head even though I know none of them are going to happen because I know he is no where near how any of my exes are. I just don't know how to keep it from affecting me and my relationship.

None of the things I usually do to help it are helping. Any tips.