Dealing with Relationship OCD

Yes I get like that often and it's brought a few relationships to end, but my current partner doesn't mind it because he knows it's a me issue, not a him issue. I've had others think it's my way of accusing them of cheating or something bad like that but at least for me I think it's just because I was raised by someone who was overprotective so it's ingrained in me as a Form of 'care' and I'll immediately jump to worst case scenario if I'm unsure that they're okay.