Eased off the weights too much?

I'm not sure what's up, I'm only able to do 30 reps per session which I am trying to do daily, I occasionally skip a day if I do other things in the course of life.

I have introduced a new set, apologies I assume everything has a name but I don't know them, from behind my head and up.

I do all my workouts with my bar, it has no weights on it but weighs a good amount on its own.

So at present I do 10 basic curls (pretty much just to warm up), 10 from behind my head then 10 curls with a lift up, if I feel up to it I try to get another 10 curls in. with a brief pause between each set.

I assume that once I adapt to the new set I can start pushing quantity again.

I'm also doing 10 half crunches (just enough to tension stomach muscles then release), hoping to push these up to 20 soon, really helps with the belly! :)

Just keep on going I suppose!