Would you care to elaborate?
Sure thing bro.
With my first proper gf, I made classic mistakes, it was a 4 year relationships, during which time we broke up twice.
I turned my sh!t around and managed to get her again, but by that point the respect for one another was almost gone.
Firstly, STOP ALL CONTACT WITH YOUR EX. ALL OF IT. THE GREATEST ASSET A MAN HAS IS HIS
ATTENTION. Giver her attention when she's done something that pleases you and withdraw it when she displeases you.
secondly, have you read the book of Pook in the DJ bible? that's a great starting point for building inner confidence and realising your place in the world.
Thirdly, you need to put your self on a path of self development, I wrote about this in another thread.
1. Build up your confidence, do this by working out, dress better, look awesome to feel awesome.
2. Get an amazing social life, make new friends, MEET NEW WOMEN (make your ex jealous= jealously is the most powerful emotion that a human can experience) go out and do new things. Push your social limits.
3. Get interesting and varied hobbies, ones that you can talk about and are fulfilling.
4. Get a job if you haven't got one, earn some $$ provide for yourself.
5. Lastly, once you've been on the path of self development for some time, your ex has to know about it (if she already doesn't) by "bumping into her" at a mutual gig. This can be a house party/birthday bash/music concert, hell it can be anywhere that both of you will be amongst many of your friends.
The last part is key, it is for her to witness your transformation and instantly regret breaking up with you. Then you play it smooth and reel her in over the following months.
Like I said, its a LONG process, you will not win her back over night, and this is only a 99% guaranteed success rate. There is a 1% chance that she has no interest left for you... but you should work on self improvement for
YOURSELF anyway
Lastly, have self respect, stay true to yourself, realise you are a man and go have some fun.