I feel guilty for everything that happened. Now I can´t sleep, I don´t eat, I´ve lost interest for everything in my life. I feel a hole inside me. I´ve also thought about hurting myself. I did everything for her to love me more everyday, but I got the opposite result. Can BPD people genuinely love? I´m disgusted by myself. I hate myself.
If I remember correctly, you didn't do anything obviously wrong, so if that's the case, there's nothing to feel guilty about.
You sound like you're going through "withdrawal." A break up is like trying to get over a drug addiction -- our bodies were flooded with chemicals that made us feel good, and suddenly they're gone. That's on top of the emotional feelings and memories. It's normal. It's tough, but people get through that all the time.
You might be confusing actual feelings of guilt with your brain trying to work through ways to save the relationship because you miss her -- that is, trying to figure out what you could have done differently to have kept her/get her back.
What you need to understand is someone with BPD (or CPTSD, anxiety, etc.) is not acting rationally. Their actions are dictated by distorted thoughts and emotions. They engage is cycles of irrational behavior -- and this is the important part: These cycles of behavior are not driven by rational thought and will happen regardless of anything you do or say. You can't prevent them. You can't predict them. They happen regardless of what you do.
So, you are not to blame for what happened. If you get back together with her, it's all but guaranteed something like what happened before will happen again. That's part of the cycle. You are not in control of that and for the most part, unless she is getting therapy (and even then), neither is she.
Your directing blame and disgust at yourself is unwarranted. You should not hate yourself. If you wish to recover quicker and better, you should focus on yourself and your healing. Eat well. Exercise. Get out and enjoy yourself and/or the company of others. The hole you feel will fill up again with good things.
In terms of people with BPD being capable of love. That's a tough one. If you read about it on the Web, some people say no and some people say yes. My experiences with my ex suggest the answer is no, at least not in the way a mentally and emotionally healthy person does.
When we're emotionally healthy, we crave the other person's presence and attention, of course. We want them to feel the same about us. More importantly, we want them to be happy, and we do things to try to make them happy. We care about their welfare and contentment. Yes, we can argue with them or be upset if they do something that troubles us. But love doesn't disappear. We don't wish them harm or do anything to harm them.
When someone is emotionally unhealthy, all that can shift. They might care more about their own happiness and welfare than the other person's. Their distorted sense of reality may cause them to do things that harm, frighten, or disorient the other person. What they think is love is something else, like infatuation or need to control. That's not to say they can't or don't care about the other person in some way, but that care never equals the attention they place on their own needs, even if those needs hurt the other person, emotionally and psychologically. I wouldn't call that love, or at least not love as I understand and experience it.
All that said, their mental illness is not their fault. They didn't ask for it. But it is their responsibility. They don't get a free pass just because they are mentally ill. That doesn't mean they should be punished necessarily or anything vindictive. It means that you or anyone else involved with someone with BPD (etc.) has to understand that ultimately, it is not their responsibility for the way they were treated by someone with BPD (etc.). You are responsible for your actions, yes, but not hers. And if your actions did not involve hate, violence, vindictiveness, gaslighting, or any other negative things people can do, then you have nothing to feel guilty about.
