Monks are just not meant to be invulnerably armored tanks. Light, dextrous, and fast is how a monk rolls.
You start putting Armor on a Monk, and you may start wondering why you have a monk. Plus, I don't see that dex + armor gives you as much as dex plus wisdom.
As you continue to adventure and acquire items, your AC will go up. But so will that of everyone else. In addition, the ability of your enemies to hit higher AC's will increase. You will likely always have a relatively low AC.
I think your best shot is being able to absorb blows, so I'd invest in a higher constitution, and take the Tough feat. In fact, since I started playing D&D in the 80's, it's been a vanishingly rare character (of ANY class) that didn't have a Con bonus. I'm running a monk now, and my Con score is higher than my Wisdom.
Healing potions are a must.
Last, consider dipping into Fighter for 2 levels. Grab 2nd wind for some self healing. And Action Surge is good for anyone.