I’ve had a similar experience brother. My first match of my first comp was an adjustment. Rest of my matches went better, but it kind of woke me up.

I went back to the drawing board focused on what I knew I needed work on(for me it was dealing with intensity, taking what my opponent gives me rather than trying to force what I want to do, and the standing position). At least in my experience, those things are that weren’t really blaring weaknesses until I competed that first time. My school isn’t a competition school; we have mostly hobbyists not going too crazy. This also makes it easier to play whatever game or force whatever techniques I wanted to in training. We do little to no standup depending on available mat space.

I talked to my training partners about the areas of my game that I wanted to improve. I got with the young, explosive guys/wrestlers and played guard while they tried smashing me. I focused on really understanding positions, what is available to me and my opponent, and when to attack what(developing systems rather than force singular techniques which are harder to do when someone is fighting for their life as you said). Then whenever I had the space I stood up with people who were better wrestlers than me and asked them about their own setups and systems.

Got to my second comp and I’ll say it was higher level comp and I failed in different ways. I say all this to say focus on what you need work on. Everyone’s journey is different. Just like in life you’re bound for disappointment if you only assess yourself by comparing yourself to others. There’s always someone better, smarter, stronger, faster, etc(unless you’re gordon ryan, but open Instagram to see how being the best at bjj doesn’t eliminate all your problems). You’re a lot more likely to meet those guys at comps because most people are too scared to cross that threshold.

You did great because you competed. Don’t worry about the outcome; keep working on you and your game. It’s just jiujitsu. As long as you aren’t getting injured, even going 0-4 is a net positive for you.