urgent help: cpanel login loop after update, can't access web hosting management or whm

i'm completely stuck and tearing my hair out. after a recent server update, my cPanel login is stuck in an endless loop. i can't get into my account, whm is also looping, and i'm totally locked out of any kind of web hosting management. this is killing me.

it's a vps, running centos 7, and i think the cpanel update was like 110.0.x or something. i applied it last night, everything seemed fine, but this morning, boom. can't access any files, databases, or even manage emails for my clients. everything's just sitting there unmanaged.

i've tried clearing browser cache, cookies, tried edge, chrome, firefox, even tried an incognito window. nope, still the same. tried logging into whm directly too, same damn loop. i ssh'd in, tried checking tail -f /usr/local/cpanel/logs/error_log and /var/log/messages, but honestly, i'm not seeing anything obvious that points to a login issue. i even tried /scripts/restartsrv_cpanel and /scripts/restartsrv_httpd just in case, no dice. i'm not even getting an error message, just redirecting straight back to the login page after i hit enter. it's infuriating.

so yeah, the problem is, i put in my username and password, hit login, and the page just reloads the login form. it doesn't even say 'invalid credentials' or anything. it just loops back. tried both cpanel.mydomain.com and mydomain.com:2083, same result. for whm, it's mydomain.com:2087, same damn thing. i can't do any basic server admin or web hosting management tasks at all. i'm losing my mind.

has anyone seen this before? what logs should i be looking at specifically? any commands i can run via ssh to debug this login loop? i need to get this fixed like, yesterday. any expert advice would be a lifesaver right now. waiting for an expert reply.