Thanks for query,
Don't put pressure on yourself to get family by some body.
Sexual performance is a mental response to organs.
When your mind is anxiety
free,without tension then only your parasympathetic nervous system
gets stimulated & you gets sexual arousal.
Erection is not affect your chances to have a family.so don't measure how strong it is.
ejeculation in fertile period needed to get pregnant your wife.
Medicine may cause erection but it is not needed in present situation.
So don't worry use correct period you will get your child in next couple of cycles.