My Lasik doctor says they overcorrect on purpose? My vision is now nearsighted and worse.

For hyperopic laser vision people do tend to over correct. One is because it accounts for regression of effect and two, because people tend to want more near as they age.It's always a good idea to demo monovision in contacts before doing any procedure. Some people just don't like monovision.

Yes, your doctor is telling the truth, during lasik we overcorrect. The eye is like a rubber band and it likes to bounce back to its original position a but after being reshaped. We overcorrect in order to compensate for eyes natural reaction to resist correction. After 3 months you should not be experiencing this effect anymore, what are you scoring on the vision test? If it doesn't subside within another 30 days I recommend searching for a second opinion. On the other hand its most likely that you just need more time.