It feels like i've bruised my arch on my right foot and it also itches. what could be causing it?

Itchy feet: Sorry you have to go thru that :-( you might be suffering from tinea pedis or.....Athletes foot. This is a very common condition that can cause all sorts of discomfort. Check your feet and see if they are peeling or cracked, even between the toes. A mild topical anti fungal may help or topical steroid cream. If the condition continues ask for a podiatry referral.