Please help me, I'm so burnt out and I don't know what to do anymore

I've been working non stop. Late nights and weekends and I'm just not catching a break. I keep getting told that our clients don't want to pay for alot of hours so we aren't allowed to code a lot of hours, despite the fact that I sometimes spend almost 3 days working on something, I code only 6 hours. I sacrifice "after hours" so that I don't code working hours to the projects. At the end of the week I'm left with hours unaccounted for despite the fact that I'm overworked. We've just had MAJOR layoffs and I'm terrified for my job, despite it all. I don't know what to do. Am I doing something wrong? I'm new to this.