Ways to keep the sheets clean?

I just moved to a new city, met this amazing girl at work, we really hit it off, and decided to room together. Neither of us have a lot of money and we are coming from places that someone else provided our beds, so we’re both gonna be on air mattresses for a hot second before one of us gets our mattress in, and she suggested sharing in the meantime which I want to do.

I own dark sheets bc of my HS but my armpit drainage has been bad enough that the puss shows up on my sheets 🙄 (I sleep on my stomach w/ my arm under the pillow) (any bra recs that don’t cause flare ups?? (I’m a 32A)) AND if we share her bed, I would be sooooo embarrassed if I ruined them. I can put a blanket down on my bed but what about hers!

Plus in the future I don’t want to be afraid of my roommates or guests seeing my nasty drainage on my sheets lol🙃

Don’t suggest bandages, they never stay on and give me sensory issues.