If I need medication for my anxiety I've been on for 15 year's and don't have a psychiatrist atm, being in the middle of changing doctor's. Can I come here for help getting my med? I have appointments just not soon enough before my meds run out?

Your previous Dr. should be able to write a script.

ERs generally don't write prescriptions for chronic conditions. Especially psychiatric meds because they can't diagnose a psychiatric condition. The only thing you would be able to do is claim you are having suicidal ideations in the ER and they will get the psychiatrist to come see you/admit you.