I hope this makes sense, but have you ever thought that maybe the problem isn't about feeling insecure in your relationship, but rather it's insecurity Towards yourself?

I used to feel, EXACTLY like you did years ago when I was younger and had my first proper relationship (he ended up being a boyfriend of 6 years and the father to my child). I was that insecure i would bottle this rage and jealously up in myself, that I couldnt even stand it when he became friends with girls on Facebook, glanced at porn magazines in shops, or even when we watched a film together and there was a hot woman in it just incase he preferred her over me!

In the end, the guy was abusive and treated me like ****, and looking back, he was the reason for most of my insecurities (another story for another time). But the raw anxiety and jealousy and paranoia dispersed over time when I started to make friends with who I was, and realised that "if they were to cheat/message/talk to other women etc, then it was THEIR loss, not mine!"

You are talking of the positive woman role model who you are seeking, but lovely, it takes time and experience and realism to really see that that woman is nobody but yourself. For me, it took a lot of pain and inappropriate choices to deal with the situation (especially when it came to harming and punishing myself), but when I looked in to who I really was on the inside, I realised it was me who was the most important person I will ever spend time with in my life, and when I saw the door slip open for self love and worth, that's when the changes started happening. All that time and effort looking after myself, and now it doesn't hurt a fraction as much. Look within. There's someone inside waiting to be loved by you x