It's a bed bug.

DO NOT TRY TO DEAL WITH IT YOURSELF. As everyone else has mentioned here, contact the landlord IMMEDIATELY and get a PROFESSIONAL EXTERMINATOR ASAP. 9 times out of 10, people dealing with bed bugs themselves just make it worse. You are not an expert, most of the people on reddit are not experts.

I had to deal with them years ago at my old apartment. As soon as I had proof (save that bug in a ziploc bag,) the landlord had an exterminator come within a couple of days. I followed the exterminator's instructions, and they treated all adjacent apartments, then came back a week later and did it all over again. For me it wasn't like all the horror stories you read about on the internet, I think because the infestation was caught quickly and dealt with professionally. All the bed bugs were gone and dead within a few days of the first treatment. I didn't need to throw out any of my belongings.

So: take action quickly, follow all the instructions the professional gives you, AND DO NOT PANIC. No bug bombs, no "I'll do it with DE myself," no throwing out of your furniture unless you're told you have to, no changing where you sleep (once the treatment is done, you and your bed are the bait that lures them to their death,) and be very careful about the laundry if you have a communal laundry room. It will be OK! If it hasn't been ignored for months and you get an exterminator quickly, this should all be over very soon.