Dude, girls are like buses as soon as one leaves another will show up. LOL
I know that is a stupid saying but really the hurt will pass. I have seen pictures of you and doubt you will have a problem replacing her. I'm not gay either, BTW, married happily.
Hang in there Matt "this too shall pass"
Keep yourself busy and don't dwell on her leaving. Read a book or take up a new hobby, something that you would not normally do, fishing, scuba diving, anything that you have wanted to do but never had time. Any way man good luck, I think if you take your mind off of her your health will get better.