Many priests have psychological training so ask around for one to talk to. I know from experience because I have bipolar disorder as well with a similar history of delusional thinking as you. I've started the RCIA process two different times, but had trouble connecting with others going through it since they typically were there to convert for marriage. For me, faith is so real, profound and even scary because I have those intense moments of grandiosity that go far beyond what a guy who wants to marry a Catholic girl would comprehend. I started asking around directly to a few local priests and found one who had an educational background in psychology and he was certain he'd be able to help me work through issues of faith and mental illness by pinpointing what experiences were genuinely spiritual as opposed to those that were symptoms of my bipolar disorder. I have been hesitant to talk with him more since our first chats, but more because I fear change and am sorta reclusive. The typical RCIA process definitely did not work for me the two times I tried it, and he says he'd be willing to walk me through the process on a one-on-one basis at my own pace. It's taking time, but it's the right path for my situation. Simply finding a Catholic psychiatrist wasn't enough for me. Maybe one who has a strong enough Catholic faith where they seriously considered becoming a priest would be able to help more. I'm not sure, but I figured I'd toss out my experience. I tried to talk to one of my former psychiatrists about my religious thinking and their solution was adding a strong antipsychotic medication to the host of pills I used to take. It didn't help at the time and caused permanent physical side effects that linger years after stopping them. I currently don't take any meds and haven't had an episode in over four years, but if the priest I am talking to ever suggests that maybe I need them I would definitely be open to taking some again. I have had the same delusions as you said you have, and I understand the shame and guilt associated with such grandiose thoughts. It's terrifying to not have a grasp on reality. A priest with the understanding of a psychologist or a psychologist with the faith of a priest is probably the best resource to figure out what is genuine spirituality and what is the bipolar disorder. Good luck.