Yes please take your bunny to a rabbit savvy vet. In the meantime, get a fresh pineapple and juice it, put it through a juicer. Syringe him some of the pineapple juice, it will help to break up the hairball or blockage. Keep him hydrated as much as you can. Is he a small rabbit or a medium rabbit? This will determine the amount of pineapple juice you can give him. Small rabbit, 5mL of pineapple juice; medium rabbit, 10mL of pineapple juice. Also I would give some baby gas meds just as a precaution, in case there is any gas. Get him moving around to loosen things up. No to gut meds, they can actually make things worse if not better. It sounds like your rabbit may have teeth issues and possibly the start of GI stasis. If you cannot get in sooner than Wednesday, please get a fresh pineapple and put it through the juicer and put the juice in a container and syringe the pineapple juice to your rabbit. Also do the gas meds. You will want to syringe water to your rabbit as well.