Same here, there's something particularly annoying about losing a fight to someone using Cupid's Arrow and 30 chocolate submarines though! I obviously need a chocolate fireguard to defend against them but I can't find it amongst the defense buildings!
That said though with the right balance in the army it PVP is quite playable, I've rebalanced my army so that my high value defense units don't attack at all and near half the army on attack is Warthogs, Flamethrower soldiers and Snipers. 90% of the time I lose 2-3 of these in each fight, so each fight costs about 60-70k before I rebalanced it was more like 200k. With a decent income and lots of loot farming I can just about cover this, I'm finding very few people with any unvaulted cash so I don't rely on that. It does mean my attack is weaker than my defense, so I can't easily go for revenge on any attackers I have to pick and chose, but after weeks of stagnation it's good to get some action.