BOA CONSTRICTOR HELP!!!?

5 month old type 1 anery boa constrictor... i recently noticed her making weird sounds at night so i watched her and she seems to be opening her mouth and what looks like gasping for air every now and then, sounds like shes sneezing... theres also black mucus coming out of her nose... please only people that know what there talking about answer!!! ive been searching to see if the mucus is her excreting salt through her nose like many reptiles do but i dno if boas do ??? it may be a respiratory infection ? help please any1 have any ideas what this is ?????