i just lost to an unarmed guy and i had full iron armor and gear, and the worst part is this isn't the first time this has happened. how do i get better at pvp?
Well first off try to get prot 3-4 diamond armour if you truly want to get better, Also try to get a sharp 3-4 Diamond sword. When you go into PVP make sure you have Instant health 2 potions, Those will save your life in some situations. If you truly want to get better try to join a clan with heal signs so you can train your MCMMO combat skills. Hope this helps.
That person most likely has unarmed skill, which is more powerful than a sharp 2/3 diamond sword and can easily take your weaker iron armour out.
Let me just start out by saying you don't "stink" at pvp. The person you were fighting was just higher skilled. The first thing I would do is go to single player and give your self iron stuff and build a room. Then spawn a bunch of mob to raise your actual PVP abilities. Second, join a good clan and train your mcmmo.