Prednisone taper

I have been on prednisone non stop for more than 18 months due to a huge flare up and now I'm feeling a bit better thanks to Cosentyx. I've started tapering it, like my rheumatology said, but I didn't receive much guidance.
I'm now down to 4mg but going from 5 to 4 has made me feel exhausted and has brought up the fatigue again.
Have you ever experience anything similar? Any advice?