The symptoms you provided (crying after orgasm, feeling lump in throat) are not related to medical disorders.
Achieving orgasm takes adequate stimulation and sexual arousal. An orgasm is closely related to the biochemical process of creating emotions. It is almost impossible to achieve orgasm without any emotion at all. However, what type of emotion would be present depends on the person herself. Different people respond with different emotions. You respond with crying, and it is completely Okay.
You might not like it, but there is nothing you can do about it. Just accept that the emotions are part of you. Please be aware that these emotions are not caused by a sad event. They simply come out of you and cannot be controlled.