I think im having "gallbladder attacks" after every meal. Should I go to the ER or just wait for a doctors appointment?

Depends how long. If you can get an appointment in the next week or 2, that's probably fine. If your symptoms and exam are consistent with gallbladder disease, you will likely need an ultrasound. If symptoms are severe and persistent, then the er is certainly appropriate.
Depends. Seeking emergency care is a must if a fever, very severe pain, jaundice (yellowing of skin or eyes) or inability to take adequate fluids develop. If there is mild-moderate pain that can be controlled at home, seeing a doctor is still advised, but can wait for a few days in the absence of other symptoms. If there is any doubt, seek sooner care- there is no guarantee that your diagnosis is right.