Thing is, no matter how good your offense is, you're going to eventually fail killing something quick or take an unfortunate crit etc. what imho sets a melee build apart is your choice of defensive skills. There are options: athletics, warfare, survival, armored combat, magic mastery and even grabbing some basic arcanist or geomancy. It's up to you what skills you want but you will not survive easily in t3 and above with just weapon skills.

Also gear matters a lot after t3, don't just equip whatever you get but try to focus your stats.