So tired

I am so exhausted I could sleep 8-9 hrs a night and 8 hours a day. Just getting over a cold which doesn't help. The only reason I can do my job is coffee. I haven't been this tired since I had mono and then pneumonia, I keep telling docs and midwives this and I don't think they get it. standing for more than 10 min is hard and sometimes I feel like I can't breathe or I am going to pass out if I don't take a nap. I know the allergy season is particularly bad and that is definitely a contributing factor.