Unfortunately, sub 1000 you have every type of bad play possible in the game, including people that can’t tell smurfs from non-smurfs. A level 161 with a ~50% win rate on their most played hero is not a smurf, in any toxic sense (throwing or boosting).
I’d suggest leaving your profile public. Some people will try to trash you based on your profile (some people will try to trash you based on anything) but most people will trust you more.
P.S.
There are a lot of silly theories about MMR and SR on these forums, and in this thread. See How Competitive Skill Rating Works (Season 14) → Summary if you care about this sort of thing.
P.P.S.
That Mei walling and harassing you is bannable. Report that when it happens.