Why am I still so depressed?

[Mathew]

I posted a question on here 2 weeks ago, here it is... Yes, I'm a person with relationship troubles but this one I can't seem to stop thinking about it. I liked this girl and so did my friend. Selfishly I said that I'd speak to her to see if she liked him but when I started talking to her, I realised that I liked her to. We started talking and I eventually said something which I strongly regret saying. Afterwards we stopped talking but then after about a week we were friends again. I got so close to her and after meeting her several times in person I asked her out and she said yes. Then my friend who also liked her found out this and was so angry words can't describe. She then turned against me and now she is with my friend who originally liked her. Yes I know this sounds pathetic but I am really confused and lost right now. I seem to be hopeless with relationships and sometimes think what's the point? If anyone's kind enough to possibly give me some advice on things like relationships and if anyone could tell me how to forget both of them as it makes me so depressed when I see them together which is everyday almost. They both dislike me because I said I didn't want to be friends but was that a bad mistake? I really don't know and this is why I'm asking for some help. I tried blocking them on things like twitter and Facebook but I unblock them to see if they ever say anything about me which they don't. I know it's pathetic but I can't help myself :'(

Someone answered that I should spend more quality time with my friends. I have been doing but seeing this couple everyday is exhausting! I'm so envious of them both. I wish they never were in my school. Can I ask why I'm so depressed? What can I do to stop it all? I think about it 24/7 and its driving me mad! I don't know what to do anymore. I cry myself to sleep sometimes. Please help me :'(