It is preferable to ventilate 24/7 exchanging the air in your space. That said, your plants will not perish if you put a timer on the fan and have it cut off for a period. I would suggest a timer that turns off the fan for 2 hours at bedtime and kicks back on after you have fallen asleep.
I would also recommend 10mg of Melatonin 1 hour before bed. Melatonin is n extremely cheap ( walmart...100 pills about $7 ) and natural relaxer ( it's not a drug ) and phukin' works wonders for me. I sleep like a teenager again, deeply and fully all night. I never wake up in the middle of the night. quite honestly, Melatonin is the best thing I ever did for myself.