Meltdown or just anger?

How do we tell the difference between a meltdown versus normal “anger”. I’ve had ASD all of my life obviously so I don’t know if I really know the difference anymore. Both feel totally overwhelming, intense, and make me feel like I’m losing or barely have any control.

I don’t generally feel like an angry person but when I meltdown (I assume) I feel rage and anguish to the point where I feel I begin to feel I almost lose control over speech and almost get scared like I could be capable of anything. Big, intense emotions clearly take a lot out of a person, so afterwards yes I feel drained, upset, and usually embarrassed or ashamed I didn’t/couldn’t handle things better or in a more “mature” way.

I suppose I am wondering because sometimes I just feel like a bad person and I am wondering if this is indeed something I could control and yet again another thing I am failing at handling for someone my intelligence level and age. I don’t have any go-to behaivors like punching myself or banging my head (though I have hit/hurt myself in moments or rage before) and other than that the description of meltdowns just sounds like anger to me? Being late-diagnosed Idk if I am just still seeing this through a forced “NT” experience I assumed I was having until recently but of course I am questioning and second guessing myself. Or maybe level 1’s don’t have the more extreme meltdown behaviors? If there is any room for doubting myself my brain always takes it bc it seems to love making me feel bad about myself but Idk maybe I deserve it.

I just know sometimes it is almost like Jekyll/Hyde but the people around me don’t seem to have such an intense reaction when they are mad unless they are totally at their wit’s end and have been bottling everything up. My reaction to smaller things (though clearly big to me) is I guess similar to a “normal” person’s near-breakdown, it seems.