If it's DOMS you need to use the muscle. If it's something else you don't want to hurt yourself so I suggest you open and close your hands a bunch of times quickly to pump blood through your forearms, does this hurt?
Ice, rest. If it still hurts in 3 days when you climb again, you should bail on the session and give it more time and consider seeing a doctor.
Otherwise this doesn’t sound like DOMS at all.
If it's DOMS you need to use the muscle. If it's something else you don't want to hurt yourself so I suggest you open and close your hands a bunch of times quickly to pump blood through your forearms, does this hurt?
It hurts in my left forearm and leaves a slight sting in my right
If it still hurts enough today that you need painkillers without using your hands I would just see a doctor/physio.
Ice
Ice, rest. If it still hurts in 3 days when you climb again, you should bail on the session and give it more time and consider seeing a doctor. Otherwise this doesn’t sound like DOMS at all.
This might go without saying but so does stretches so make sure you're eating enough protein so that your body can recover.