OP, ther are pages and pages of threads here from women who have been/still are in relationships with varying degrees of abuse and plenty of tragic aftermath threads.
Trouble is many women find themselves 'caught' with a couple of DCs, no money and an arsehole of a DP/DH who makes their lives miserable and hellish, wondering how they got there. However, if you ask most of them, it was a slippery slide with a couple of red flags at first which they either thought they could sort out or consigned to the back of their subconcious only realising later that, deep down, they knew all along the relationship just wasn't quite right.
You have posted your issue with DP here and you know full well that hes wrong yet you then defend his ridiculous demands of you because he has issues; which you then think you can help him with.
He is telling you about his view of women, if he is friendly with them, he wants to fuck them, he has an ulterior motive. Hes not concerned with your feelings otherwise he wouldn't make such a demand that you give up a friend of yours. You cannot speak for him, help him or change him.
If you want the best a relationship can give you, you have to listen to what you want first and I would bet if you think about it, there are more ways in which your DP is upsetting you than you will freely admit to at this time.
Don't wait until its too late to really make a difference, don't accept second best and above all, listen to your inner voice as it can reveal an awful lot