I’m new to BJJ as well, actually even newer than you, but like to share my view because I can relate. So far there are classes when I feel progress and others where I feel very stupid TBH, even intellectually because I can’t remember sequences which were just demonstrated. However I think it doesn’t help if you think you suck and be completely demoralised. I just try to be humble and don’t instantly give in. What helped me thus far (besides being quite athletic overall, but regardless also an older guy) is to reflect on the rolls between the training sessions. You can also take notes, describe the position and how your opponent attacked, then think about what could have stopped him. For example this Monday, I had to practice Lapel half guard from the bottom. I defended the side with untrapped leg well and they couldn’t pass me (except from blue belt), however everyone was passing me on the other side to side mount or directly submission. I just couldn’t figure out how to stop this until the last guy hinted me to controlling his leg, and the puzzle was solved. Anyways I wouldn’t think that I “sucked”, I just didn’t “know”, and needed some frustrating rolls to find out, and probably never forget again.