Breakup after 3,5 years.

Hi, I don't really know where to start.. I've been in a realationship for the past 3,5 years. Throughout this time, my ex and I had so much in common, would always show love to eachother and always be there for eachother. Before the realationship I was 15 and depressed. After we had come together it all changed and I never felt the same again. I had broken up a few times but always managed to be there for her because she felt bad which resulted in us coming back together. After that, I didn't break up once and we were really in love. Now 3 years later we were still the same but all of a sudden she came and said that the realationship doesn't work anymore. I really didn't know what to say other than we can work on it. We went on holiday and had a good time but after that week, after every day she was working, she went out with her friends. So 7 days later, 7 days she went out with friends, she decided to tell me that she doesn't see the point in the realationship anymore. At the time I thought that she just needs space because she kept messaging me a few times a day. I gave her the space but she just doesn't want to react at all. Today (exactly one week) I felt the worst I have ever felt. I have been crying all day and called her a few times too often. All she wants to do is get her things and then that's it. I really love her and I think she still loves me too but I don't know what to do anymore. I feel so bad and every other minute im thinking about just vanishing. What would happen if I would be gone? Would she care for me? Would she be there for me if I overdosed? I cant get this out of my head and am feeling extremely lonely. She is out everyday with her friends and is doing things.. I'm going out everyday too but am still feeling really really empty.

I would appreciate if some of you would give me tips on how to overcome this or just give me some details on self-experience. Thanks a lot!