/r/destructivereaders is basically for this, although they require you to critique others before submitting your own work. I don't know of other sites that do this though. Maybe we could start a #writersworkshop tag over here?
As rd95 said below to follow the tag #writebetterdammit Honestly, I'd rather stay away from reddit for a little while so all that can cool down. I might just stay away in general. If I can't get help on it here, though, I'll go there! Thanks!
Hey, Grimdark_Rainbow, quick tip. To make a tag linkable, border it with the "#" symbol. That way, #writebetterdamnit becomes #writebetterdamnit.
Scribophile is a whole community website devoted to what you described. I found it hard to critique enough work to post my own and there are deadlines after which a work can't be critiqued, like a month or two weeks, I don't remember. There was virtually nothing I wanted to critique so I didn't use it very long but I thought it was worth mentioning.