The difference between an unloomed set and a loomed one is notable, but not tremendous. Loom items because you like them, not to become overpowered. If you expect to be significantly harder to kill by DTV bots just because your loomed your stuff, you are expecting the wrong thing.
Level 20 is very weak though, impossible to have a fair chance in PVP and very hard to be good against bots, too. Getting oneshot by a Maul in the head is very likely, regardless of the helmet. However, also a level 30 build can be very diversified (shield skill, riding skill, horse archery, PD, PT, split wpf, ...) and just as weak as a level 20 build.
Bots weren't buffed or anything; compared to before, the stats are weaker, but the unglitchable maps and the increased bot number compensate it again.
In summary: Deal with it or become a better player.