Right, sad to hear about your poor uncle's death; 71 is still quite young really too. You will be upset about your uncle; & obviously worrying about your Dad bless him, it must be horrible to lose a sibling.
So you will have to be strong for him; as well as grieving yourself which is hard. & i expect your Mum & brother will be in the same position really.
It's going to feel a bit awkward to see your brother after 10 years; but you will have common ground to concentrate on (comforting your parents & feeling upset about your uncle).
It's really hard to forget nasty stuff people say; but 10 years is a long time & your brother probably regrets his words (but being a bloke is not likely to say so!). As a younger brother he probably didn't know what being a 'crap mother' actually is; & just for whatever reason chose to say that because it would upset you. I bet you weren't crap at all.
He will have changed a lot hopefully in those years; as will you.
Hopefully you can get to know each other again slowly; & rebuild your relationship if you feel ready to.
As for your son - ask any older child if you are a 'crap parent' & they will say 'yes' especially if they are 12... take it with a pinch of salt. :)
If you are worrying that you are a crap Mum then that means you aren't crap.
(Parents who actually are crap won't worry about being crap)
I'm having a 
& doing my nails in a min. I'm worrying about my job; that helps take my mind off things. take care xx