It is easy to give advice to stay together, to try again, etc. But only the person who has suffered knows the pains of what that entails. So, lady, let me give you a practical advice and a legal one (although not a lawyer!):
Practical advice: Evaluate the situation from a long-term perspective. With a few sacrifices from your side, can you two get together for the child's sake. Does he love the child? Is he violent? Is he an alcoholic? Is he a capable earner to feed the family? These are important questions you need to answer to come to a decision. And no lawyer can help you in this analysis.
Legal advice: If he wants to withdraw the petition but you want it to continue, then the procedurally correct way to do so is for you to file a counter-petition or a counter-claim or a cross-claim (whatever that is called in legal terminology here) for a divorce based upon your grounds, whatever they be. This way you can use the current petition to pursue your claim without the need to file a fresh one. However, there may be time limitations but there probably are ways to ask for condonation of the same. I think that the cross-petition has to be filed at the time of filing the Written Statement. I am not too sure but what I am suggesting is the correct approach to do what you want to... Also, the new law may favor you so it may be worth waiting. I feel sorry for you because you are a mother with a newborn.
One more thing... there is some discussion here about advocates... Be very careful about advocates in general. Most of them are IDIOTs. However, Adv. Kalaiselvan's general advise is worth considering if you can think of your baby's future... GOOD LUCK!