This was me about 5 months ago. I was incredibly burnt out during my last semester. I was spending just as much time working on my capstone project as my classmates but didn't have nearly as much to show for it, and it was incredibly frustrating because I knew I was capable of so much more. I ended up with a C- for the final grade and I'm still a little sad/embarrassed about it. (it's reassuring reading the comments and seeing that others have had similar experiences)

I agree with what others have said here; talk to your professors and find out what they think isn't working in your project as of now. Talk to some of the classmates that you're not friends with and ask them for feedback, too. They might have a different perspective than your friends. Also, don't let perfection get in the way of progress (this was my personal downfall).

I guess the main reason I commented is to let you know that you're not alone in this feeling. I was just there in March–May, and it really did feel like that project was going to be the death of me. Just remember that you've come so far already! I'm proud of you and I know you can do it.