I honestly don't know where to post this but I'm so so so so sorry if I'm wrong (always am)

I keep thinking my significant other is gonna break up with me and they keep saying they aren't but I don't believe them cause every other relationship I've been in THEY have broken up with me, cause I'm not enough or I'm dumb, ugly, can't think straight, can't stop saying suicidal things..I'm probably just being dumb about all of this to be honest.
When I think of losing someone or something important to me I'll cry and my brain will go into autopilot thinking of how I'll lose them or that thing and it'll keep going until I'm just crying and I snap out of it...Then I can barely remember what happened I'm starting to shake just writing about this and breathe heavily.

I'll have these moments ( Very Rarely, mostly after a breakup or something like that ) where I'll become very sad, depressed, suicidal where I'll just lose control and start hurting myself in any way I can, I have messed up my arms and legs when these periods of time have come around and nobody knows about this except for a couple people that probably didn't even care but listened anyway so I'm just gonna put this on here to see if anyone can help or point me in the right direction to find out what's wrong.
When these moments come I can barely remember most of it...but some parts I do and they scare me and regret doing those things but I can't help it, it just happens.
The two biggest times this has happened I tried to..do not alive..

Sometimes when I look around the walls and floors will be moving and I'll see things start to come at me from my peripheral vision and I try to just ignore it and pretend it's not there but then it gets closer and I'm about to cry when this happens, and I'll look at it and it just disappears. These are the times when I'm paranoid for whatever reason and it usually lasts about an hour? I think? I don't know. The last time this happened it lasted all night and through the morning, I could not sleep I stayed up all night crying, scared, and I was shaking throughout the entire day after that, I probably sound dumb so I'm gonna stop. ;~;

There's other things that I think aren't normal but I can't remember them cause bad memory.

What's wrong with me? I can't take it..

I don't know if there's anyone here who can diagnose that, honestly.

It's important that you seek professional help, I think, because what you're experiencing is definitely not supposed to happen. But it's not something wrong with you in any more meaningful a way than being sick or having a cold is something wrong with someone else. It's just illness, and illness is often normal and commonplace but it's never good, so it's something you shouldn't simply accept as some burden you have to bear by yourself.

Tell the people you love and trust what you are going through. Ask for help. You very likely can get help, and you very likely can get better, but you need to trust someone.

welp..

You might have relationship OCD (R-OCD).

EdenIsh, our brains are such complex things that experiencing weird perceptual stuff is not really a sign that you're falling apart. Not at all. You're under a burden of emotional stress and other stuff, which is going to have effects on your health and thinking. I mean, just sleep deprivation can make a person hallucinate. Doesn't mean the person's brain is broken, but it needs sleep, less stress and good health again.

Depression really makes for faulty memory too. I know that myself.

It's a shame that you seem to be self-harming in not one but two ways. It seems to me that when you start believing someone's going to break up with you, that this is just your self-harm habit doing it. What I mean is: your mind is inventing stuff to upset and worry you about your relationship. It's a sort of self-sabotage and is kind of like cutting, in some ways. A lot of us do it, to different degrees. The thoughts of this type probably don't have much to do with the actual relationship at all.

So that says to me that your relationships might fail not because they didn't love you -- it's simply because a difficult habit you have got in the way. All this is my opinion, anyway.