Brief Answer:
Completely normal and fit for sexual life.
Detailed Answer:
Hi there,
Thanks for writing to us,
It is completely normal, do not panic first of all.
As you said earlier your penis size decreases as you bath, it is totally normal as
cold stimulates the contraction of the external genitalia, which looks like constricted.
As you have put up some weight, I need you to lose some weight, as your tummy grows, you feel like your penis getting contracted, but it has nothing to do with the sex life.
Avoid
stress first, as it is the most common cause of
impotence.so do not panic and
masturbation is completely normal.
Some people might have excess foreskin covering their
glans, looks like it engulfs the penis, and that to completely normal.
As a whole you are completely normal, and fit for sexual life, no worries needed.
Take care.