Stress and anxiety. Take to feel better.

I am a software engineer with 3 years of experience. I have been assigned to a new project recently (1 month), where work load is more and I am very stressed. I feel anxiety most of the time and being worried about minute things ( though they have no impact) all the time. I never had sleep issues but these days I can't sleep properly. I feel anxious all the time and feel like crying for no reason. I get severe shoulder pain because of stress. I can feel some kind of pressure on my hands, I have cultivated the habit of rubbing my palms (didn't have before). And my periods are also late (2 days for now), usually they're on time. I can't stop overthinking about everything and being worried. I am unable to focus on my daily activities. And my work productivity also reduced though I am working for 11-12 hours a day as I can't focus. Please suggest measures to take to feel better.