Kinda having some complicated feelings...I never told my boyfriend the "L" word yet because I'm kinda afraid.

Last time I did, it was all great until my last relationship changed...and I got my heart crushed over and over, took me a very long time but I got over it and moved on after my parents death.
I met my good friend, who is now the one person I care about so much that it hurts...because I found out he's in love with some other girl and it was before he met me. I decided to just let him go because I didn't wanna get hurt even tho I was, he told me I'm worth so much to him and that even if I was to leave him, I'm stuck with him because he doesn't wanna leave me and he doesn't want us to break apart because again, I'm worth so much to him.

So for now, we still spend time seeing each other, we talk when we're away from each other, he is still seeing this girl who is also now my friend...she's nice, but I still get that feeling that if I was to tell her how I feel about him she'll pick a fight which I don't want, she refuses to share him while I honestly don't care...we're not married, and even tho I don't wanna share him with anyone else all I want is him to be happy, but I feel he'll be more happy with me. The girl is kinda negative tho, she kinda gets upset easily and they've had their breaks 3 times already...while we never got mad at each other, we have drove each other crazy but that's it.

I'm scared that if I tell my boyfriend how I feel he'll look at me differently even tho he's said many times that no matter he would never think any less of me, but I had my heart broken so many times I'm just...scared because I don't wanna lose him as a friend and I don't want her hating me or whatever else may happen.

So I'm wondering if I should just let it go and remain friends or just tell him the truth.