I feel guilty for saying this but I’m exhausted

My babe is 6 months. He has given me 9-11 hours of uninterrupted sleep since he was 3 weeks old (not a brag I’m just providing context). I wouldn’t say he’s a chill baby but he’s not super fussy either. Naps are hit or miss, some days are really good and other days are crap. But I am EXHAUSTED. I’ve had blood work done, I try to work out 4x a week but every day I feel absolutely drained. I do 95% of the morning feeds (which can be anywhere from 4-6 am). Most days my baby wakes up at 6 ready to start his day. I feel guilty for saying this because I know there is so much worse out there but what the hell is wrong with me. We also formula feed so I feel like I shouldn’t be this way but I’m struggling. I live in Canada so I’m thinking it’s the cold and the dark days, hoping when it gets warmer I won’t feel this way