is it bad that i feel good about donating blood simply because i know that my blood will flow through another bro's erection?

No reason for it to be bad. Most likely will go to some old grandma who needs blood. So odds of it pumping through another guy's erection is unlikely.

and what about the blood that you donate that might flow through women and their bodies, does that make you feel good?

lmao. That's not what the recipient usually thinks; it's more that they are grateful for being alive.

if you makes you feel good than do it don't have to ask to help others

hahaha fair enough