Put on 2 steroids and antibiotic for severe asthma/chronic sinusitis. O2 levels dropped 97 to 79 just walking. Can I drink coffee while on steroids?

Uncontrolled severe. Persistent asthma, is what you described, you need more rigorous treatment and follow up, you might need more meds, need to limit your activity for now and avoid all known triggers, steroids can cause gastric inflammation/irritation,you may want to have some gut prophylaxis as well (ranitidine or pantoprazole), please see your doctor again asap and keep close follow up to avoid ER /hospitalization.
Mgt. You can drink coffee, but steroid can cause GI upset. If you are having trouble walking even while on steroids, additional medication is needed.