Help! Girlfriend broken up with me, I'm too clingy?

Me and my Girlfriend of 10/11 months have had a very heavy relationship, were both insanely in love with each other but we tend to bicker and argue a hell of a lot. I've lost my temper many times and we've broken up over it, by lose my temper i just mean shouting and swearing not abusive but it was never a serious full on break up we always kept in touch. Then on friday i was texting her a lot while she was out with friends and she had already told me she feels rude texting back while shes with friends. I ignored that and carried on texting her anyway and started asking why she was being so short and had i done something wrong as i was just a little worried because this was after all those arguments. Then not long after that we had a huge row over it, she came round with my stuff and it was over. We spoke not long after it, she was saying she couldn't do it anymore and she didnt want the stress. I didnt contact her saturday morning or afternoon and i caught her after work, and gave her a letter and told her to read it once she was home, it was asking her to meet me to talk it over, and she stood me up. She was with a friend last night, and was pretty damn harsh down the phone and i was drunk, she told me to just go away and not contact her at all. But being drunk i ended up sending her thousands of messages looking like an idiot, she also told me a boy had been messaging her asking her out on a date last night and today, she said she refused as she still loves me but cant be doing with me. I tried swiftly moving on when drunk but as soon as a girl came onto me i couldn't do it, and ended up saying i had a girlfriend. We spoke today and she was still pretty harsh and said shed rather i left her alone and didnt speak to her because the drunk messages had pissed her off. So i sent her one last long text explaining i knew why she had had enough of me, and that im more than willing to change, and that maybe if i dont contact her she will believe me when i say i wont be clingy. So we havent spoke now since this morning, i'm obviously worrying about that boy texting her and worrying if shes ever gonna get back in touch, i need some help or advice badly and would appreciate any sensible ideas, especially from someone whos had a similar situation before