Please help! i have horrible seasonal allergies but why only when i'm inside?

Not 'seasonal': Your reaction is more likely a result of an irritant which is common to your indoor environments. Look around when you begin to have symptoms and try to find a common theme. Also, it may not be true allergies so, consider a consultation with an ENT or allergist who can help you solve then treat this puzzle.

Indoor allergies: If you are symptomatic indoors, then it means you might be allergic to dust mites, mold, and pet dander, to name a few common allergens. You should get medical advice on environmental control, medical treatment, and possibly allergy testing. Then, you may be a candidate for allergy immunotherapy.