From someone who's been doing keto for several years now.
A: Pre-Keto, odds are you we underestimating how many calories you were eating. Unless you were tracking every single thing you ate, there is a high probability you just didn't realize how many calories you were consuming.
B: It is super hard to over eat on Keto. It is possible, take lots of liquid calories in (heavy cream can do this easily!), and there are some other real screw ups, but eating 3000 calories of steak is pretty damn hard.
C: What you are reporting is common for people who have a lot of weight to lose. At some point it becomes a lot harder, at first you just have to sort of watch things, then you eventually do have to count calories. (Especially if you want a six pack, holy crap do you have to count calories!)