Mind fluctuating wildly..verging on insanity

Dude. She's a manipulative bitch. Doesn't deserve you at all. Leave her and move on.

Don't be so self indulgent. She is a bitch and you seem ok. just i dunno meet up with someone new and be done with this slut

how am i being self-indulgent? I'm worried about this behaviour of mine and need help..

its self indulgent because there is nothing wrong, you dont need help- its perfectly normal to send hate texts to a horrible ex. Ok if you were stalking her/ sending her anthrax then you might need help.

She sounds like a manipulative horrible girl.

she calls me last night and asks me why i'm being so horrible to her..and I don't know why ..I just didn't have the heart to tell her ..because you're a characterless slag who's ruined my life..she said she can't handle this any longer and begged me to stop sending her such texts...

Ah- just tell her "look yo-yo knickers, I sent you texts because you have been such a bitch, think yourself ******* lucky I haven't done anything worse."

I've been through a really bad breakup last month where my ex gf told me that she still had feelings for her ex and didn't think we were compatible..and dumped me. I loved her to death and have been heartbroken since then. I've tried to think of how badly she treated me and how she lied to me and tried to convince myself to hate her. At times, I do hate her but I know, deep down, I do love her.
I ended up sending her a lot of hate texts a few days ago...it was basically just an outpouring of my emotions. I thought I should move on and asked a mate of mine to set me up with another girl. I am going to meet this girl next week. However, I did a very stupid thing yesterday. I went and told my ex that I am meeting this girl. She started calling me names and said that I lied to her throughout our relationship and I didn't really love her at all. She said if I loved her, I would have tried to make sure she was ok instead of sending her hate messages(she dumped me though?). She also said that if I loved her, I would have tried to 'win her back' and continued loving her despite the fact that we were not together. She said she was glad she broke up with me cos I was a scumbag.
This has got me very depressed. My confidence has hit an all-time low. I can't see myself ever getting with this new girl who my friend is going to set me up with because I can't see what she'll see in me. I cancelled all my social outings for the weekend due to depression and also didn't go to the gym today.
At one point, I feel that I can get this girl and I start feeling all happy. Just the next minute however, I start getting negative and feel that I am useless and do stupid things. My thoughts and mind is fluctuating wildly and I fear that if I don't get a grip on myself, I will either go insane or commit suicide one day. What do I do?
P.S.: This is not a troll post or me asking for pity. I am actually pretty annoyed at myself but cannot control my behaviour.

Your love sick just like most of us on this forum..
it's a rough time, and it lasts ******* ages. One minute Ull feel like your old self, the next you want to kill yourself.
There's a couple things that help me through these rough patches.. there only temporary fixes but it's what i do to keep myself from going insane from time to time.

1) Your Friends (Spending time with them will make you forget for a little while)
2) Music (None of that lovey dovey music, just feel good music.. listen to some frank sinatra or something)
3) Gym (work on yourself, always works)
4) Other girls - When your in love.. i no you don't want to get with another girl.. im not telling you to. But just spending time with other girls can ease the pain.

Good luck mate, if you ever need anything inbox me.

thanks for the help..i do want to get with this other girl i've been eyeing for the past week and my mate says he'll set me up with her...
I have however lost all my self-confidence and don't know how to pull her..