Mental illness in relationship

I’ve had bipolar disorder since I was 14 and had one hospitalization. With a doctor’s approval, I went off of meds when I was 17 and now Im 19 and in a serious relationship. I feel like I manage my disorder well and It took time, but I learned that my disorder does not define me. However, I have not told my lover yet and I’m afraid of how he’s going to react. Im scared he’s going to break up with me because he thinks it wont work out with my disorder or that he’ll stereotype me and my experience with my disorder. Also, Im afraid he’s going to think I lied to him by waiting so long to tell him. Part of me doesn’t want to ever tell him because its my personal issue to deal with and Im not even on meds anymore. That doesn’t change the fact that I still have it but it means to me that I’m not in the worst condition ever where my disorder is controlling my life. Part of me feels like telling him about my disorder and risking him breaking up with me gives power to my disorder but I want an honest relationship with him and he is my support system. What should I do? How should I tell him? And does anyone have experience with this?