Thank you, Wes. The cause of my nervous breakdown is a woman with whom our continued relationship is questionable. I've always laughed at such situations whenever someone tells me about them. I don't know what happened to me; it's so unlike me; I've never felt anything like this before, and I'm ashamed that I fell so deeply in love with her that I can't imagine life without her
The first thing you need to do is sit down and honestly ask yourself "am I better off with her or without her? Today? Next week? Next year?" Make a list of reasons why you either are or are not. But come to the answer from a state of logical thinking. Don't let emotions cloud your judgements. If this was your best friend, what would you tell him? Once you have that answer and list then decide how you are going to go from where you are now to the best outcome for YOU in the long run.
Don't try to meet someone new to get over her. You will only compare that person to her and it is unfair. Especially if the other person is a decent person.
Don't turn to alcohol or mind altering substances. They will only inflame emotions further.
Don't stop training, but don't train super hard. Your CNS is already going to be stressed just from this situation.
Don't stalk her - or let her stalk you - so refrain from any contact with her unless children/pets are involved.
Don't underestimate how long it will hurt. Once you get ran over by a dump truck, things are just going to be bad for a while. Don't blame yourself or take it out on others. It's just the nature of things. It is supposed to hurt. If it didn't, then it wasn't really love to begin with. True love doesn't go away easy.
You got this. It's just going to take a while and it is going to teach you about yourself as well.