How do I know if I should break up with someone or stay with her even if it’s causing me harm? I love my partner a lot, which is why I can’t imagine life without her, but she always threatens to leave me for someone else when we fight, which is why I feel so threatened. I can’t see her with anyone else, and she exploits this, which is why I have thoughts about ending this relationship even though I know it will make me miserable for a long time. I am always conflicted and can’t make up my mind because for every good day we have together, there are three bad days of anger and sadness. What should I do?
You have to weigh the consequences of your feelings against the damage to your physical or mental well-being. Relationships don’t rely upon love alone, because 
there are other aspects involved. Two people with different personalities, interests, and expectations are trying to build something, and strong feelings aren’t the only things that can support this idea. If you don’t feel respected, and she makes you feel insecure by threatening to be with other people, this isn’t a sign of love. It’s emotional abuse because someone is exploiting your vulnerabilities and making it harder for you to feel secure. Tell her why this is wrong, ask if she wants to change her attitude towards this relationship and, if nothing happens to address this, you should put yourself first and make a decision based on your health above everything else.

I don’t think my ex-boyfriend will ever let me move on because he still monitors whom I am on dates with. It’s obsessive behaviour and I don’t know what to do. Please help.
If you want this person out of your life and he isn’t going, you may have to consider legal options. Speak to family and friends, and have someone inform him that his behaviour is upsetting. You are an adult with rights and are entitled to your boundaries.