I had not even thought about donating my sperm. ( Does anyone even want Trans sperm?

)
I guess, as selfish as it is, I feel the need to reproduce. I think I'm pretty awesome!
While I think it would be better for the world if I adopted, if it is at all possible, I would like to contribute to the gene pool.
At the same time, I know that I must transition, and I cannot wait around to do that.
So if I donate it and someone uses it, that would make me a lot happier. If that is my only course of action.
I would be interested in storing the sperm for about 10 years.
I'm going to have to ask around, but this is quite possibly the scariest part of transition I've faced. Has anyone else dealt with this?
Impotence, check. Losing beard, check. Changing body, health problems..all of it..I don't care. Coming out and taking hormones has made me feel happier than I ever have in my life. But I'm terrified about this kid thing! I want to create another little ginger!

Ok, so I am waxing emotional here, but seriously: I am terrified. This is the only hurdle I've really stumbled on.
Finally...
How likely is sterility? I realize that I need to operate under the assumption that sterility will occur, but are there any established medical/scientific studies which indicate a percentage of how many T-Girls become sterile after several years of hormone treatment?
Thank you all very, very much. I will be posting here for many years to come, hopefully.
Solace!
Ganbatte!
~Brihannala