Is it normal to feel like you're faking your mental illness?

I kind of feel like this. I was recently diagnosed with bipolar disorder, unspecified, and the unspecified part makes me think they were just confused by what was going on and settled on that. It also seems like I have OCD according to my therapist/psychiatrist, and I cannot always tell the two apart. For example, I sometimes get irritability/racing thoughts and had a mixed episode I was told, but some of that could be OCD related (although not likely to the extreme I experienced). My friends say they don't think I have bipolar disorder, and they have known me a long time but they are not doctors. So yea, sometimes I feel like I am faking it, especially since I can be totally "fine" a lot of the time and it doesn't feel like me when I am unwell.

It’s not so much that I feel like I’m faking it. But when I’m manic I believe I’m well.

What Guiness said. I question myself as to whether I overexaggerated my symptoms during my evaluations by different providers, four of whom diagnosed me with bipolar 1. I don't think I did, but when I'm completely well I tease myself by thinking "hey, maybe I'm not bipolar after all." I know, it's ridiculous and I seriously doubt anyone who knows me IRL would believe for a minute that I don't have the illness. But even seven years after diagnosis and several major mood episodes plus a hospitalization, I'm still not quite convinced.

44 here. Dx'd at 29 with bipolar 2.

I often think I am faking. I am mostly depressed and rarely go manic, so I tend to think it can't be "bipolar."

Right now I am pretty stable. I started Latuda and it's helped A LOT with the depression. But because the depression is under wraps, I am thinking maybe I don't need the Latuda.

I think it's cyclical. Unless you stick with your DX you're likely to go off med and undermine your progress. It's not only natural to feel you're acting, or making it up, it's part of the illness.