have you ever just cried for no reason

[TutTutButt]

just that really.
I miss my mum. I miss my ex. I wish I did a lot of things different.

That’s not nothing. They sound pretty valid reasons for tears.

That sounds more as if you're putting pressure on yourself to get over things you haven't quite gotten over (indeed some of them you may never fully get over, e.g. missing your mum ).

I am on the depo jab for contraception and for me it’s perfect except for the few days after I have a top up I am an emotional mess.
I’ve cried because of an advert, not even one of the emotional charity ones, a ridiculous non emotional one...
I’ve cried because I knew I was being sensitive and I didn’t need to cry about things
I cried because I told DP I’d do the dishes whilst he was at work and I was working evenings and I couldn’t be bothered in the end!

I think a good cry now and then is healthy even if it’s for no ‘real’ reason.
You sound like you have valid reasons to cry, I hope you feel able to seek help if you need it but crying in itself isn’t too bad!