My DS1 is almost 3yo and while he has been a good sleeper, he is waking a lot more than usual these days. Usually once a night, occasionally twice. He used to never wake! So I am similarly frustrated. Most of the time he doesn't need anything but reassurance, and I am in and out of there quickly after a tuck in and a kiss. I don't know what is going on with him but I have noticed that recently he is scared of a lot of things. He is always saying he is scared, and of the dark particularly. We bought him a nightlight and for 2 nights he sttn, but then went back to waking. So I am at a bit of a loss! I am thinking that at this age they start to understand fear and being scared, and are very much affected by different things throughout the day. i.e. scared of the dark, thunder, bugs, scary things on tv, intense movies, loud noises, etc. I was going to post soon actually asking if this is normal for the age, which I'm sure it is. It sounds like you might be experiencing something similar? But it is worse for you it sounds since your DS never slept as well to begin with.
I don't think it's a routine issue, your routine is somewhat similar to ours in terms of amount of sleep.
Right now I try not to get too upset since it just seems he needs reassurance, kwim? I am hoping it will pass! Maybe someone else will have some more ideas for us!