This game is meant to be hard :-). I'm not sure if don't charge enough. Bombs start with 10lp and your max damage is 20. So you need to charge at least half of the time to kill them with one shot. With every round bombs get 2 more lp.
Also don't stuck in the mid. Try get as much distance as possible between the top clock hand and you. So it is also important were you are on the map. A safe spot will always be only kind of temporary.