False memories destroying my life

Hi, a little nervous as this is currently my first time actually talking on a forum but recently I’ve been going through an extremely rough time and there’s one thing on my mind that is effecting my relationship, and that is false memories. So I’ve been suffering from extreme anxiety and also paranoia for many years now, bpd has also been discussed. so for I’d say 4 years I had been struggling with depression, all relationships were awful including my first one which has greatly impacted my life, extreme mental and physical abuse, but now I have found someone who for the first time ever has shown me how beautiful life can be and has given me genuine happiness, now since we’ve been together I have been tormented by my mind, I have done stupid things in the past and even tho they may seem very minor to most people to me the thought of him finding out feels like life over !! So this has gradually been getting worse, and I feel that bc being depressed was the “norm” to my mind and may I say I am not good with change so my brain is not liking this new feeling of happiness it is experiencing, so a few nights ago something happened, I woke up with a weird feeling, like something bad had happened, I usually wake up feeling like this but this time it was different, and throughout the day an image popped in my mind, of fb chat and some guys name and the picture, now this is all that is in my mind, I woke up checked all my messages, search bars and there was absolutely nothing, and I know deep down this isn’t real just it felt so real, and to this day I have been creating all these details and I have literally brainwashed myself, I’ve been trying to reassure myself that nothing happened, firstly I am a very deep sleeper and have never done anything like go on my phone in my sleep, also I know when I’m awake, just my brain Is like hmm I wonder what thing could possibly destroy this happiness and relationship?? And obviously cheating is usually a relationship ender so it’s like my brain is trying to make me believe I’ve done something as if it’s not allowing me to be happy, when I have paranoid dreams I never remember anything apart from the tiny segment of the dream that caused the paranoia, I also want to make the fact that I’m extremely loyal to my partner and am genuinely disgusted by cheating , just I need the reassurance from other people that this definitely is just my imagination drifting, the worst part of all this is the extreme guilt I have, I’ve been suicidal these past few days as the guilt is so overwhelming, I also experience dream reality confusion, which is common in sufferers of bpd but only recent has it been that I’ve discovered that these symptoms I have been experiencing are linked to ocd, so I finally discovered this great forum and would literally mean the absolute world to me if someone could help, as this is honestly destroying my life, and not just this situation I mean as a whole, mental illness has taken over my entire life, years of attempted therapy and now on the journey to get medication, just would love reassurance and hopefully find that maybe someone here has experienced the same and it’s not just me,
Thanks :)

Hiya, I understand completely what you are going through out of no where around a year ago this false memories popped into my head to the extent that I couldn't face being in work it made me feel disgusting that I was even having the thoughts I would cry every single day because I didn't understand why this was happening to me after being happy for so long then after a year it passed and I even managed to come off my tablets because I felt so good. Then all of a sudden around 3 weeks ago the thoughts came back stronger but more powerful than last time my partner couldn't understand what was wrong and no one understood why its come back again my doctor told me it must be something in my past that's making me like it but literally nothing has happened to me. I promise you it does get better but you need to try and keep telling your mind no this is not me these are thoughts there is no action to them but I know what your going through because my mind creates memories that seem so clear that I think oh that must of happened