Hi there Uvaraj,
Another explanation for your seeing semen in your urine is because, while masturbating and just before you ejaculate, you are squeezing your penis and causing yourself to have retrograde ejaculation
This is not your real problem however. Your real problem is guilt. You say "I feel guilty". This is inappropriate guilt and is part of what's called the DHAT syndrome. Please try and stop feeling guilty about masturbation
. Until you can do this you will not start to feel better about yourself. Masturbation is a universal, healthy and normal part of sexual expression.
I wish you well.