Does my situation sound like a manic episode ? (undiagnosed)

Over the past couple months I’m starting to feel more and more in my gut that i had a manic episode. Late February i would say it started. I showed signs of obsession towards my goal at the time which was bodybuilding, feeling amazing and like i was almost untouchable. Felt really irritated by small things especially when it came to my at the time gf. Had trouble sleeping to the point where i decided to take melatonin for the first time ever in my life, sometimes it worked sometimes it didn’t. I also did risky behaviors like cheating and wanting to do risky sexual acts. I kept ignoring my gf everytime she would tell me how upset she was in the relationship and i would just not care/listen. I became so full of myself i remember one night i was at the gym till 3:30am, finished doing my workout and after that i was looking at myself in the mirror taking selfies/videos shirtless for over 30mins straight i kid you not. My close friend tells me “ you were the last person i would’ve ever thought would do something like that “ and my gf told me that i behaved like an entirely different person throughout this time. I also have trouble accepting that i actually behaved this way, of course i did. But it’s a weird feeling that i just can’t wrap my head around because i know myself to be way better than i know i would never do things like that. Especially the cheating part. I still can’t believe it every day that goes by.