Questioning

Hey all, so lately I've been really conflicted about whether I have BPD or not. For some background, I'm 18, never been abused or anything like that, however I do have a history of being abandoned by those I consider(ed) friends. This goes all the way back to first grade. In my opinion it's always been their fault, because I can never remember doing anything that would cause them to leave. Nonetheless, it has severely screwed me up.
As far as the criteria, I nearly always agree with 5-6 of them, but it seems that reading about it makes me want to act out in the other ways (whether conciously or not) Is this part of the unstable sense of self? As far as life choices, once I find something I'm pretty set on it and invest a fairly large amount of time/money/etc on it. The downside is that I rarely stick with it for longer than a year or two at the most.
I started noticing last year how quickly my moods could change, especially in regard to those I attached to. As is seemingly common, my need to be around them basically 24/7 just drove them away, which of course threw me into a spell of self-harm (still do it), hating them but still wanting to be with them, etc. Despite this I can have half decent relationships with certain other people? Anyway, I've talked to two therapists about it (although briefly, I'm not one for opening up or telling the truth in those situations) and they didn't believe I had it. I guess I'm just looking for another perspective?

It is always hard or even near impossible for someone that doesn't know you to tell if you have BPD or meet the criteria for it. That's what therapists are for.

You seem to have looked into it yourself and according to you, you meet 5-6 criteria, so you might have it, but we can't really confirm that.

Some advice if you actually do wanna be diagnosed, try getting several diagnoses from different therapists. Many missdiagnose disorders, especially BPD, sometimes because they don't know how to treat BPD, sometimes because they don't want to and it's easier for them to treat if they simply diagnose you with Bipolar for example.