I’m so stressed and I’ve been thinking too much about a situation and haven’t been sleeping at all at night. My friend is talking to my ex and I’m still in love with him ?

Im sorry to hear that. I understand that having a friend talking to your ex can be stressful. In my experience, it helps to talk to the friend in question and work through what's going on. Sometimes your friend might know something you don't, or it can also sometimes be a misunderstanding. Its important to realize that friends are often more important than romantic partners. Usually its not worth losing a friend over an ex. If you're not sleeping at night, this may be the cause. If you continue to be unable to fall asleep after this situation is resolved, see your doctor.