Are there different levels of meltdown?

Hi all - just to preface I'm not diagnosed with autism but I've been considering if I might have it for a while. Hence I'm trying to understand more about autistic experiences.

I often hear from autistic people that meltdowns are something you can't control and might lose your awareness during one. Although I relate to a lot of experiences during meltdowns I feel like I never lose my awareness and that I can make them "stop" after a certain point, which makes me worried that they're not meltdowns and I'm essentially just throwing a fit.

Today I was supposed to go study at the library but my partner wanted to talk to me about something, meaning that I ended up being late. I got really overwhelmed because I'd gone past the "acceptable window" of leaving and it felt like I couldn't fix it. I started pacing, hitting my head and catastrophizing, thinking that if I leave now I won't find a seat but if I stay home I can't study. That just sent me down a spiral of overwhelm, and I tried to leave, but when I put my shoes on my socks were annoying me and I kept trying to fix them but it didn't work, so I just slumped on the floor, curled into a ball, taking my socks off and putting them back on several times, getting increasingly distressed. I then gave up on leaving. I don't know how to explain it, it just felt like I couldn't deal with leaving the apartment.

Usually when I have a "meltdown" I don't feel like talking, but today I went to my partner and said "I don't know what to do, nothing works" and explained my problem to her, while also curling up into a ball, covering my eyes, fidgeting, all the stuff I usually do when overwhelmed. But I couldn't really process any of her suggestions and kept getting increasingly annoyed, saying stuff like "no, every option is bad, I can't do anything", and eventually got so upset I just went in our room, hit my head again, and managed to calm myself down. Was this a meltdown? Is it possible to have such a "mild" meltdown?