What has made you stop caring about your eating habits? Was it something you were more mindful of before? If yes, then consider how you can bring the focus back to your self growth. If this is starting to affect your self esteem, think about how you can take care of yourself and presue your goals. A better sense of self will help you deal effectively with such issues.
Its not your fault.Thats not love! Your boyfriend was just attracted towards you. A person is much more than just outer appearance. You are beautiful the way you are. Move on!
Be yourself and love yourself don’t have to put efforts for that idiot.
You should start going to some gym/fitness centre/start doing any physical activity which will help you to control your eating habits and also at the same time, by making him understand that looks don’t matter, but the persons nature and heart does.
It's never too late to start looking after yourself.
It's difficult to comment because I don't know the severity of the situation.
I understand that your partner likes slim woman but if he's just encouraged you to work out then that's okay. He cares about you and wants to see his partner look gorgeous and I see no harm in that! You both should work towards your own self for the sake of each other.
Having said that, if he's constantly mocking you over for your weight and making you feel unhappy about yourself then that's alarming. Then, firstly you should make sure he doesn't keep doing this. There's always a way of saying and going about with things! Rest is your choice!