Are these feelings normal?

I broke up wit jason a month back. Then i became friends wit Tom,who also happens to be my ex. Jason found out bou our friendshp and thot that we back together,nw he is trying to rekindle things with hs ex and i am so NOT liking that! I thot i wasnt into Jason but i cant help feeling like he is betraying me,coz he tld me that he wil never go back to his ex. To make things worse, i talk to his ex.and she tels me that they friends 4 NOW. Im startin to hate her. I dont want to get back with him, but i dont want him with her. HELP!