Wow you should tell him. If you truly love and adore this man and vice versa, he's not going to care. Does he know about your current friendship with her? The longer you dont say anything the more it will pose doubt in his mind. Like why couldnt you share that with me? Do you not trust me? Believe me, my husband hasnt told me things about past relationships which I later find out through his mom and sets things in my mind. Its important to tell him, yes its your past but it shouldnt have a bearing on your relationship now.
As far as she is concerned you NEED to tell her to back off! You value your friendship but you need some down time, youre not her caretaker anylonger. By allowing her to control the situation it sets you back from your current relationship. She almost holds it over your head. She's fully aware of your relationship and may have some jealousy issues but you have to set the boundaries!
everything happens for a reason...beginning to wonder why.