You appear to me as a mature and caring father. Waiting for another 1.5yr would give you no benefits. If i was you, i would
- Wait for 3 months and gather enough/strong evidences
- If you can then offer the wife a one time alimony and take the custody of the child. Im suggesting taking custody as it appears your wife is neglecting / not handling the child properly.
- If point 2 doesnt work then with help of strong evidences file for Divorce on cruelty grounds. Your evidences should be strong enough to prove your wife is NEGLECTING the child....... stronger the evidences easier will be the settlement/MCD.
Also be prepared for false cases from wife's side............if you plan carefully you can counter her false cases with help of evidences.
One fact is that no matter how much you LOVE/care for the child , once the custody goes to the mother, the child will be influenced by her and you will be emotionally drained and frustrated as child will not be able to give you back the same love in return.
Better focus on taking care of your responsibilities as a father , life will be relatively easy. Getting custody of child is very difficult my dear so think wise and dont waste precious years of your life .........