Sorry to hear you have severe anxiety. Getting up and getting moving should help. Neurontin (Gabapentin) will not make a dent in anxiety. There are ways you can learn to channel your anxiety and your doctor's office might be able to get you a referral. Unchecked anxiety can lead to worsening MS symptoms or simply MS-like symptoms.
Making a determined effort to move forward is an excellent way to put anxiety into "check". Today is today and tomorrow's problems will always be tomorrow. Just keep taking a day at a time. There may be days when you indeed need to spend the day resting.
Stay away from pity-parties and you can go far. Please be mindful of your physical limits and do not go over the redline. Expect occasional setbacks and plan for alternatives for those days. Still keeping you in my prayers,