Okay first for some history:

I have been in long term relationships with almost no single time for most of my adult life. I am in the process of swallowing TRP and it has come with some pretty interesting realizations. For the most part, I see myself as somewhere between beta and alpha. In all of my relationships, I had no issue picking up and seducing the girl. The beginning has always been the same; it feels sincere, like there is real connection and I play into. I allow both of us to believe this is 'true love'. But at about a years time in the relationship, the sex gets stale and I started rationalizing that it was only infatuation not 'true love' and slowly, almost painfully slow, broke the relationship off. I had made the decision to end it months prior in both cases and took it as slow as possible to sort of ease them in and make it appear like it was just growing our separate ways. I would then rationalize to myself why what I did was normal to avoid the guilty feeling that followed. Fast forward to now. I am with a girl who I have some serious concerns may go crazy if I break up with her. I have been having sex sans condom for a long time with her (she used hormonal bc). But upon reading TRP, I decided that was a choice that needs correcting and started using protection (hurray for using my brain). In terms of breaking this off, how to I best protect myself? I am having serious anxiety about her coming up to me with the 'I am pregnant' line and me being cuckoled. All advice welcomed!