Hello there,
It can be tiresome to change Psychiatrists over time. At times medicines may surprise you with side effects. Alternate therapies include Psychotherapy with an experienced Psychiatrist. However, to answer your ques, ECT is better option than Ketamine therapy.
Your treating Psychiatrist is the best person to take that call.
Next Steps
Consult a Psychotherapist
Health Tips
You also need a thorough case evaluation.