Beforehand appologies for long post.

Long backstory relatively short: I met one guy and fell in love with him. Let's call him Sam. After two/three weeks we started dating with some drunk confessions involved. While dating Sam I fell for another guy, Lee. I woke up from the pink cloud and realized I was going way too fast with Sam and ended up breaking up, partly for Lee. It all went really messed up and I was single, Lee still with his girlfriend. 

A few months pass. A second 2 month relationship that never should've started. Never been so unhappy because the pink cloud disappeared after already a week. Started cheating with guy 3. Broke up with number 2 and started dating 3 after waiting for like a month or more. 

Fast forward a month of dating number 3, I now realize he might be another mistake. But he is suicidal and depressed, so leaving is impossible. 

Now the whole point of this post. I recently started talking with Sam again after around 6 months no contact. It was some chatting at first, nights and nigths of long talking came back. Then a week ago we went out for coffee. Nothing happened, just some long missed talking again. After the 'coffee date' he asked THE question: why did you start talking to me again? I answered honestly for a change: I missed him, I really did. Yesterday we met again, watched some series at first, nothing serious. But halfway we started talking and ended up telling each other how much we miss eachother. We kissed, we had sex, it was amazing. He knows about me being in a relationship and we're unsure what we want to do from now on. He knows about my BPD and knows this is not uncommon behaviour for me. He opened my eyes, I'm going to get proffesional help tomorrow and he says he wants to help me, even though he is not sure what to expect from me.

Right now all I can think of is just... Starting over my entire life and try it again with him. I honestly believe he *is* what I need; he has the patience, the wisdom to help me through this and I feel that with him by my side I might finally be faithful for once. But I am so, so terrified that this is once again the BPD speakin for me. That I am about to give it all up for another 2 month relationship. A voice tells me that after knowing Sam for a year I must know him well enough that the thrills are gone and this *might* be serious, but another voice tells me this is all fake again. I really don't know what to think.

Not sure where I was heading or what advice I am looking for. Thanks for listening.