Welcome to HCM
You are taking steroids
for connective tissue
disorder namely Dermatomysitis, You are in a phase where dose of steroid is being tapered.
I presume your disease must be in control as far as ESR
is concerned please do not worry it is a marker of inflammatory state and has prognostic value that means if it shows continuous declining readings the disease is improving.
Your Fasting blood sugar may be due to steroids as they are known to increase blood sugar but keep a watch as your dose is reduced,In the mean time take diabetic diet and walk regularly if you can.
Once your steroids are tapered off recheck FBS and PPBS after 15 days to make sure you are not diabetic,may also get HBA1c
to know status of blood sugar in past.
Please take care