[Njxatsbf]

My question is this that if i do the meditation very sincerily, may the bads inside me will automatically be erased or i have to strictly abide the five moral disciplines first?

Shekhar,as Aloka has written try and live a moral live,but very important is to be gentle with yourself.
Please don't try and become Enlightened over-night.
Go at your own speed,yes try to bear in mind what your trying to do,this may mean pushing it a little,but not too much.
Some people are more restless than others so maybe a walking meditation is more appropriate.
Hang in and it will work for you.