He didn't say it.
https://www.quora.com/Did-Einstein-really-say-to-stay-away-from-negative-people
There's also
I usually fact check these things, but oh well, if he didn't say it I still agree with it 100%.
As for this:
Where do I begin?
We are not scientists dealing with very serious issues, we are people who should be empowering ourselves to make a difference. There is no comparison. You are looking for every reason why we shouldn't fight for this cause which I believe is weak minded.
Either we unite and make a serious amount of noise or we sit and wallow.
Your approach is to do nothing. Why bother? You say. This is not the mentality to have if you want to go out and achieve things. It's clear we won't agree.