Doing it at home is an option I had never even condiered, I'm not sure that's the wisest approach, but I could be wrong.
The reason to preserve your sperm is because hormone replacement therapy generally drops your sperm count to a point that you are infertile (and can also often result in dry orgasms where you don't ejaculate)
My advice would be to look for a well reviewed, highly regarded fertility center in your area and go talk to them about the process and what it'd cost