Why when I ended the relationship...I'm the one who's Heartbroken?

I'm sorry if this does not make any sense my head is all over the place at the moment.

I'm really confused with my feelings...

I recently decided to end the relationship of 4 years. She was a single mum of a little lad who I adored so much and treated him like my own. We all got on really well like a proper family. However she was really difficult to talk too, she would never be consistent and would have mood swings out of the blue without any warning. I couldn't talk to her about serious stuff as she was away with the fairy's! There are plenty of other reason why I knew deep down she wasn't the one (I don't want to talk bad about her she is a lovely girl).

The problem is I'm so attracted to her and love her to bits. I need to be strong and make sure I don't go running back because I know it would be wrong thing to do.

We said we will stay friends and meet up mainly for little man sake. I will 100% do this but its going to hurt seeing her especially when she gets in another relationship.

The thing is ever since I ended the relationship. I've been so upset crying most nights and can't think of anything else. I MISS HER! I try to get out of the house but this is not helping seeing happy couples together.

I don't know why I feel like this? I just want to give her a massive cuddle... this is the problem I'm so attracted to her.

I have a massive heart and really wanted to find ways to make it work.