I’ve been using fluticasone propionate and just sprayed 2 sprays in each nostril about 20 minutes ago before I got in bed. I am unable to sleep because I have so much nasal congestion and I can’t breathe great. Can I use Afrin spray in addition?

Yes you can. but don't exceed recommended dosage / duration, usually not more than few days, till the steroid nasal spray starts to work, also make sure you use the right technique for applying a nasal spray : ' look at your toes while spraying your nose' , point towards your ear not your eye, while the sprayer is inside your nose, (e.g. use the left hand to spray the right nostril), and finally sniff gently.