Is it normal i'm depressed becasue of this?

Here's the story step by step:

1. Introduce my GF to my friends and one of my friends develops a crush on my GF.

2. They start texting on a daily basis (she was texting him during a movie we were watching and she stayed up till 3am texting him).

3. My 'friend' starts quizing me on my own GF, showing me a picture of HER friend and asking me what her name was.

4. She makes me break up with her after an arguement, but she agrees to get back together eventually. After the break up my friend goes behind my back and says basically says "well me and his ex GF have more in common than (I did) her".

5. I go round my females friends house (because i haven't seen her in ages) and we end up kissing, she makes me choose between her of my ex GF (i choose her and i regret it now).

6. I had to tell my Ex GF that i chose my female friend, she gets angry (i really really regret it now).

7. I ask my ex if we can meet up so i can take her back. She tells me to fuck off.

8. Female friend finds out, she tells me to fuck off.

9. Now my ex is dating my 'friend' whom i see everyday.

10. Now i'm angry and depressed because i lost 3 people that are close to me and now i feel like i have no one to talk to.

Help me.