You play weak NT, which is why you didn't fancy opening in 3rd seat
1C = 5-card majors, either 12-14 balanced without 4 diamonds, or natural, or any good 17-bad 20 balanced without a 5-card major
1H = spades
dbl = lead directional
redbl = either strong balanced with HHx or better in hearts, or a club/heart reverse.
OK, you are in a hole.
Now what, if anything?