I've been using this site since 2004. It has both the House and Senate maps.
Senate map:
https://www.270towin.com/2018-senate-election/
4 Democrat seats are considered toss-ups.
2 Republican seats are considered toss-ups.
If the Democrats win all 6 and there are no surprises, the Senate will be 51-49 Democrat. Currently it's 51-49 Republcian.
That said, there are several other states where the Democrat is considered to only have a slight advantage.
House map:
https://www.270towin.com/2018-house-election/
3 Democrat seats are considered toss-ups
16 Republican seats are considered toss-ups
If the Democrats win all 19 and there are no surprises, the House will be 219-212 Republican. Currently it's 238-193 Republican. There are 4 vacant seats, and I'm not sure what's going on there. The total should be 435.
The gerrymandering case is supposed to be decided this summer. If they decide it's not their business to do anything about it, I think the states will become even more emboldened and things will get a lot worse, but I don't think it'll affect 2018.
If they decide to do something about it, things should get better, but it may not affect 2018 except maybe with a few of the states that have already made some decisions (assuming they actually stick). E.g. if the Pennsylvania decision sticks, the House numbers may change a little in the Democrats' favor.
Anecdote: I was talking politics with my mom, who is 70, today. She used to vote almost 100% down the Republican party line, up through the late 90's. She kinda started to drift away from that starting in 2000 but still voted for a lot of Republicans. She told me she might never vote for a Republican again because of Trump and what the GOP is doing about him (nothing).