Hello dear..
First of all remove all myths & misconceptions from your mind about
masturbation.
In fact, Masturbation is completely normal & doesn't have any bad effect to the body and mind.
Please do not get apprehensive regarding the left side bent of your penis.
In absence of any other symptoms, curvature of penis to either right or left side can be considered as a normal anatomical variation.
And it will not cause any hindrance in performance of sexual intercourse or conceiving.
Performance can be improved by having a diet rich in fruits, vegetables, fish, nuts & honey.
Avoid stress...practice
meditation..this helps in improving concentration & builds up the confidence level.
Avoid
smoking & alcohol.
You can also do oil
massage of the penis...it increases blood flow & maintains the erection.
Despite these measures, if you experience difficulty, it will be better to rule out other causes like
high blood pressure, blood sugar and other local causes that impair blood flow to the genital organ.
Please let me know if you have any further queries.
You can ask me a direct query on this website using the below link: http://www.healthcaremagic.com/doctors/dr-polash-sannigrahi/64925
Wishing you a good health.
Take care.