No, a rabbit in a smaller space may take smaller hops, but will still use their hind end normally. And they won't be grinding their teeth due to pain.
It sounds to me like she may have injured something in her hind end. If it was an internal issue with her stomach or organs, that will usually cause a rabbit to stop eating and drinking due to the internal pain. The fact she's still wanting to keep eating but is grinding her teeth in pain, and is reluctant to hop normally, sounds like an injury to me.
The vet will probably need to do xrays, as there's a good chance it's something higher up like the hip or spine. An injury lower in the leg, will usually just cause the rabbit to hold up and not use the leg that's injured. It may not be an injury that can be surgically repaired. The vet may just recommend cage rest for several weeks to months, to limit moving around and aggravating the injury, and allow time for the injury to heal on it's own. Also the vet will need to prescribe some pain medication.
The cage rest is something I'd start right away, so any possible injury isn't further aggravated until the vet can check it. So small level area with no steps or ramp to have to use. Also not picking bunny up if at all possible, as this will be very painful if there is an injury. If outdoors, either bring indoors, or closely monitor bun is staying warm. Then get her checked asap.
https://wabbitwiki.com/wiki/Broken_bones