Managing stress with puppy

Hello!

I am first time dog owner. My mini Aussie Shepard is living with me in an apartment for 20 days now. He is sensitive by nature, and overall a good boy. He sometimes triggers hard outside when we go to potty and he sees other people and wants to jump on them or get's startled and barks a lot. That is not always and we try to work on that. Biggest issue is that he is not sleeping for long periods of time, max 2 hours at time, and then wake time I try to limit, but still he can go over 3 hours of wake time. I know that he is overtired and overstimulated. Crate training is going tough, he does start to cry with anxiety if I leave ( we do all the stuff recommended, eat meals there, playtime, small increments there ). I have looked into play pens, but it's hard to fit crate and playpen in apartment ( it is not small. but still space is limited at some point)

My question is is it normal that out of those 20 days 19 have been full of stress for big chunks of a day? My brain is quite fried right now, since to that he is also not sleeping through nigh, he wakes at 11:30 from evening nap, I have to take him out, it's usually 40 minutes in that time for him to settle, but then he wakes again around 5 am, so I get maybe 3 hours of sleep a nigh. What is the worst, if I try to nap on coach when he sleeps, he immediately wakes and starts barking and jumping on the coach. As I said, my brain is fried, I don't know if my question even makes sense, but any advice for settling would be great.