CRC errors are bad, and the fact that those are near end means they are errors the modem picks up on the incoming signal - meaning that the frames coming into the modem are damaged in some way and the modem must request they be resent, which slows down your connection. Upstream margins are also getting a bit high which can lead to instability. You didn't show the rate at which the modem is synced - that can help with diagnosis. Mostly what this looks like is line trouble.
The first thing you want to test is a connection directly to your NID. Find the box where it comes into the house of the street - there will be a test jack on the circuit that your DSL is on. You might need to run an extension cord to get power out there - so plan how to do that before you start moving things around (makes your life easier). Plug the modem in to the test jack and then plug a laptop directly into the modem. Watch the stats on the modem for several hours and see if the errors continue.
If you see no further errors, then the issue is the wiring between the posts on the NID and the wall jack. I'd first replace the jack in the wall, and then if that doesn't work, try replacing the cable.
If you do still see errors at the test jack, then the issue could be the modem or more likely is an issue between the DSLAM and the test jack. This is the point where you call your ISP and ask them to do a plugged/unplugged test (validates the modem) and a line test. They'll see what error codes they receive and go from there.