having a BPD on assumption and just broke up with my girlfriend

[nmsh]

so, im a bisexual girl, please do not judge me for this. since 6 years ago i met a girl and fell in love, we've been dated for 4 years and through the bad and good conditions together. Actually i haven't check to any psiciatry but im sure that i have BPD. im 19 now and my gf is 20.when we argued, i always ended say i want to break up, but she dooesnt want to. she is so patient to me even she know about my BPD. i have a bad enough mood swing, but i think she is my soulmate because she always be able to calm me down. the way she look at me makes me believe that she loves me and will end up in good relationship that we'll grow old together. 6 months ago, she cheated and left me, im so depressed because she treated me really bad.but after i can forgive her and try to move on, she came back and 2 months ago we try it all over. but now, suddenly, she left me because she thinks i will much happier if she is not around, it makes me more depressed. i cant let her go, nor move on. leaving alone is so hard because im to depending on her this whole time. im so afraid that i cant love again, and im so afraid that i cant start my new single life.