Please help with insecurity!

I will get straight to the point, I am incredibly jealous and insecure. I'm not excusing it or saying it is a good thing, but it is a fact. I have an anxious attachment style which I'm sure doesn't help. I want to be a better partner, because since I have had my baby my insecurity has been amplified. The most ridiculous situations are riling me - my partner commenting that someone on television looked pretty, him giving his brother's partner too much attention following the birth of their new baby, even him telling me about his teenage crushes. Sometimes I will even be watching a show ALONE and see a woman I imagine my partner would find attractive and become annoyed. Please please help. I don't want to be like this!