Hi Catalina,
Firstly I would ask you the reasons why you want him back when you admit you were miserable with him, and all he did was irritate you?
I suspect you are feeling quite rejected at the moment, and perhaps now he is a challenge, you find him more interesting. The feeling of rejection and hurt pride often has us chasing after the wrong relationship for acceptance. Yearning for him is only holding you back from being with someone you're more suited with.
I would take this one as a lesson learned and apply it to finding someone who you find less irritating, who you will want to treat better. You could also send your ex a nice message to say you realise now you weren't compatible, and you both need to move on, but you think he is a great guy for somebody else, and wish him happiness for the future.
By Siobhan Copland
www.catchmecupid.co.uk