Do allergies affect singing?

i started singing lessons about a year and a half ago to learn to sing in "the mix", i get the hang of it but since i NEVER practiced i havent got far, but now i've been very determined (i'm 16 now) and i sit at my piano and try to sing or do warm ups everyday. HOWEVER, i do have horrible allergies... i was wondering on what i could do to help my voice.. i'm taking singulair, allegra, nasonex (prescribed by my doctor) in order to help my allergies. But, i still have TONS of mucus, i keep having to cough it up, i tried mucinex but i don't think it helps all that much. i'm on so much medication right now haha (nasonex, singulair, allegra, mucinex for now...) belagh does allergies affect yoru singing? how can i sing while i have allergies. my teacher thinks my vocal chords are sore because of all my post nasal drip, so my sniging doesnt come out clear (even though i'm singing each note correctly)... it's also EXTREMELY wobbly at times even though i'm not straining. AGH singers, please help me, i'm pretty desperate