She left you because you have a micro penis?! Well, you need someone with knowledge, someone less ignorant and who can be sensitive to others' feelings.
Sorry for the aggresivity, but I can't stand people who leave others because they have or lack something that shouldn't be relevant.
According to what I have read, the size of the penis doesn't matter when it comes to pleasure felt. The study was done by pioneering researchers Masters & Johnson. They did a huge study on human sexuality, and debunked a lot of myths, one of them being the size of the penis matters. It doesn't.
You shouldn't think you wanna die, you deserve to live, and a partner who can value who you are and what you can do, not some blue-ideal prince who doesn't exist but in chick-flicks and porno movies.
No offense, but you have no business being with people like that. You need something much higher and noble than that. And I am sure that person will appear.
Again, I apologize for my aggressivity, but it pains me a lot when things like this happen to others. I feel frustrated because I can never do anything to solv those problems in the world, but that's another story
What matter is you, and your thinking. I'd suggest you to see a therapist who can understand your situation and appreciate your sensitivity. She will make you see how worthy you are, and that the size of a penis is just like hair color or nose shape. Nothing to worry about
Best wishes always.