Thanks for query,
Shape of penis is due to its musculature & normally it is curved towards one side in resting as well as in erected condition.
The pain during erection is due to stretching of tissue.
Sex is in our mind & not in organ.
So just don't look at its shape & divert your mind from frequent masturbation
Try some yoga
.You have no disease .You can satisfy your wife.
Tension free mind gets better sexual response.