Question - Meltdowns?

So I'm still finding my way through a recent diagnosis at 27 and am trying to understand meltdowns, I believe I have them, but to read about them as a general thing they sound a lot more intense than my experience. I would assume they vary greatly from person to person, so as individuals (please call me out if it's too personal) what do they look and feel like? Are there specific triggers? - and also, are they maskable? Like if something were to happen in public, is it possible to hold it in until you're home or somewhere quiet? I read online again (same post) as a general thing that they are uncontrollable, but how far does masking go with it? 

I'm sorry if it's too personal Worried I'm just trying to understand myself a little better.