I get it up to 1435m/s (with heavy additions and changes) before running out. I think you're gonna have to design a better rocket from scratch. One big tip: make your payload as wide as the build screen, and use a probe.
I have redone my design and now make it to space. Also very close to LEO but always run out of fuel before reaching it. Do you see any flaws in my design? Or you can’t help me anymore?
Well, the first step would be to make those two Hawks their normal size... Aside from that:
You have too many stages. Combine every two stages into one. See how far that gets you.
What do you mean make the Hawks their normal size? I use three different engines- Hawks, Valiant, and Peregrine.
I removed the separators to show the engines.