My knee hurts from squatting heavy weights. should i continue squatting , rest, or see a doctor?

Weak muscle groups: Likely your legs are not balance in their strength. This will lead to knee joint instability when you squat and pain. I would recommend rest and physical therapy to get exercises that specifically target the weak muscles and consider getting someone to check your form

If you have pain: All the time, even when you are not squatting, then seeking a formal evaluation from a physician, like an orthopedic surgeon or a physiatrist is reasonable. If you only have pain when squatting, you first may want to review your form with a certified personal trainer to make sure suboptimal form isn't contributing to your pain.