Sweetie, are you seeing a therapist? The only way you're going to get to the core of this horrible sadness it by seeing a therapist who will help you get to the root of it, and learn to cope with it. If you don't you'll continue to have these terrible feelings of sadness where you don't know what's wrong.

So can you talk to your medical doctor and have him refer you to a good therapist? He will know who you should go to. Then you can make an appt. to get in as soon as possible. Sometimes the wait is quite awhile, so the sooner you can call the better.
I do hope you will try therapy. You can't go to just a few sessions and think it will help. You've got to go quite awhile before you see any improvement. I've been thru therapy and it was the best think I've ever done for myself. I hope you'll do it. God bless, and please take care. Hugs, Lee