You can get nice clothes at the thrift store! If you have some nice pants, just either pick your best sweater OR go buy a $3 top at the thrift store that fits OR borrow something from a friend. Just something that looks reasonably put together and fits, not sloppy.
That's why I was asking what to wear. I may leave early from work and go thrift a blazer or something that fits. You'll laugh but there is a nice thrift store close to my work that is 50% off on Wednesday for seniors. They carded me when I asked for the discount. lol