Rick gave good advice. My personal experience is that if I'm drained and flaring, then the medication needs a dose change and if that doesn't work, I might need to try a new med.
I want to bring up something that might or might not apply. I had the Pfizer vaccine and one booster back in Oct or Nov. I became extremely lethargic and for 3 months I was sleeping about 14 hours a day. This is NOT what I do. I had all kinds of tests...nothing unusal showed up. Eventually I got back to my normal. Is it vaccine related? Who knows? All I know is that Humira worked for me for almost 15 years.....and it's working for me now. But that three month stretch was exhausting.
My point is that flaring and lethargy don't ALWAYS have to be RA related. But it should certainly be the first thing to look at.