How do I end it?

So there is this guy, he is very handsome and sweet. He knows how to treat a woman and most importantly he treats me like a Queen. I really like him. But I am still madly in love with my Ex boyfriend 😪 we broke up on terms that’s... fixable I guess you can say but I decided not too. As much as I really like my guy friend, I think about my ex a lot. It’s like I can’t stop thinking about him. I don’t want to keep stringing the new guy along while I’m still thinking about another man, I don’t feel that is fair because it will only hold him back and me. This was not suppose to happen. We were just enjoying each other’s time and now I have fell for him a bit and I still partially want to be with my ex even though we may not get back together, I think about him all day. Idk when I will be ready to be in Another relationship so I don’t want to string him along. Every time I talk to my guy friend, I get nervous and don’t know how to tell him. I NEED HELP!! I don’t want to end it with him in a bad notes because he is a great friend. So are there ways I can do it nice and easy?