Another recommendation, make use of the fact that pawns can be raised immediately upon death, so you can sit back and let them pick on stuff.
You said you wanted to be melee...so why'd you pick mystic knight? They're not terribly awesome for melee use. You'd have better luck ignoring the bow and using a strider, or better yet a warrior or fighter if you must have a shield. Mystic knights are great when maxed out, but only after picking up a substantial amount of dp for upgrades to their spells. Otherwise, warriors hit way harder and get clout and bastion (20% to offense and defense respectively). Mystic Knight is more mdef oriented. If anything, level as a sorcerer for a while to build some magic attack.
I still say try assassin. It's arguably the best class as far as melee is considered.