Yes, but. It's possible to do just about anything to yourself but not recommended. Adult circumcision can be a bloody operation and seeing one's own blood spewing from an incision can make the most stall wort woozy. It is an outpatient procedure that can be done with a local anesthesia. I strongly recommend urologic consultation.
Self circumcisation. It may be possible but it is a terrible idea. Very dangerous idea. To have these thoughts may indicate a psychological problem and you should discuss this with your doctor to get help.
Are You Crazy ???? Of course it is possible, but the risk of serious complications is unbelievable.If you are refering to biblical reports of abraham doing the surgery upon himself, it is possible, but still ridiculus in this day and age.
Possible but stupid. Possible if you are a surgeon or urologist, none of these specialists would be stupid enough to do such a thing. No one else should try it unless they are insane, and even then shouldn't.