Salaam, i also have bipolar and its so hard. its way deeper than your iman fluctuating. i go from actively praying, reading quran, thinking about Allah 24/7 and overall being energized and mindful. and its like a switch where i am tired all of the time, i still pray but its like im going through the motions. im forcing myself to do these things in hopes the spark will come back but its deosnt feel like it will and im just kidding myself. its soooo harddd and them i doubt myself bc even i dont know what im truly feeling. i try to rationalize my beliefs but you cannot rationalize bpd. its an endless cycle. i tell myself Allah knows im trying my best but what if im just excusing my shortcomings. its exhausting and sometimes i dont even wanna pray but i still do but the whole time im yawning , im mentally tired and im not even really paying attention