steroids and antibiotics

Hi

I'm new on here and just wanted a wee bit of advice,,, Ive had asthma for years,,well controlled on seratide,salbutamol and singulair..but about 6 weeks ago I had a chest infection for which I had erythamycin,,it seemed to clear a fair bit but since then I have had a terrible cough when I exert myself or go into different temperatures, like in and out of the cold and into warm rooms,,Ive always had this but my reliever usually helps...anyway in the last four weeks, Ive had 40mg predisolone for 5 days, then a countdown course of predisolone,then 50mg a day for 5 days along with erythamycin, then this week I have again 50mg predisolone for 5 days and 100mg a day of doxycycline.....I do feel a bit better but have terrible dizzyness and weakness...anyone else experienced theses medicines and what was the outcome...cough is still here but definitely getting better.

thanks so much for reading