Your profile says you're 28. Is this true, because you sound like a much much younger person. Am I right that you're saying this is all over a person you have never once met in person? This is something teenagers go through, and perhaps this is your first experience, if an online relationship can be called that given this person could be anyone or no one since you've never met in the flesh, with a relationship, but relationships are hard, endings are hard, maintaining them is hard. they are full of joy but also of pain. By 28 we've usually gone through this a few times so it's not a surprise that it's hard. No way to say if you suffer from anxiety from this, and OCD is a particular form of anxiety, but if everyone who ever had a really hard time in a relationship were judged to suffer from a mental illness the whole population of Earth would be confined to mental hospitals. You need someone adult to talk to who can help you decide what's going on -- if there are psychologists where you are, consider seeing one. Peace.