Do I still need the J1 waiver, with approved H1b?

Whether or not you need a J waiver depends on the type of J you have and whether you are subject to the 2-year foreign residency requirement. Normally you would not have been granted the H petition unless the waiver was taken care of, you were not subject to the 2 year foreign residency requirement, or you are a medical doctor working in a medically underserved area and already have a waiver.

If you had Waiver condition in your visa, you could not have been able to get H-1B visa. Please check your J-1 visa stamp in the passport.

your J-1 more likely did not have the 2 year foreign residency attached to it, look at your visa and see if notation is made subjecting you to it. if not, then you can safelt travel back and obtain your H stamp in the passport.

I agree with my colleagues that you were subject to the waiver requirement, your H-1B petition should not have been approved. Since it was, you are probably fine. But USCIS does make mistakes. If your J-1 visa states that you are subject to the waiver, you have a problem and need to talk to your attorney before you travel.