My Feet Hurt Really Bad. They Burn And Feel Like

My feet hurt really bad. They burn and feel like I have needles sticking in them. My legs and ankles are swelling daily. My job has me doing quite a bit of sitting but I make sure to get up early in the morning and go for about a 2.5 mile walk before I head to work. The burning sensation is not going away and I cant figure out what is wrong. Any suggestions?

Thank you!