After you build your first tank you need to build a welder. You also need either a radar, llt or defender near your factory to protect it. The first option requires one of your units to stay behind and defend.

RADRAR RADAR RADAR. You've built adv radar really really late into the game while you should have made the standard, cheap radar much earlier.

Tanks weren't the best pick for this map because they have problems with expanding and Titan has a lot of expansion posibility.

You just sat in your base while Helwor was taking the rest of the map.

You moved your army in weird places instead of attacking and harrasing Helwor directly (its really important for tanks in 1v1s). Without any pressure from your part you just allowed Helwor to expand and build up a huge airforce that you didn't even scout.

tl;dr: EXPAND EXPAND EXPAND. Build radar. Exert pressure on the enemies.

Hope this helps.

Anymore?
I didn't actually find his base, because I saw no outer indication I was actually near..