It appears you may be in the UK. If so, maybe Headway can refer you to someone who has a better understanding of your needs. Headway - the brain injury association | Headway

You may have an injury to the facial or trigeminal nerves. Chapter 5: Facial sensations & movements

Is there a Neuro Rehabilitation Hospital and Clinic near you? They usually have the specialists that can help.

What about your neck? The subtle neck injuries are not usually painful but they usually respond to ice or anti-inflammatory meds, ibuprofen, aspirin, etc. Neck inflammation even without pain can cause many of the symptoms you are experiencing.

It is important to not sleep during the day. It is the wrong like of sleep. The brain only heals during proper quality sleep with all of the stages that happen at night. Finding very simple tasks like sitting in a chair doing something with your hands will stimulate blood flow to your brain.

Read the Vitamins sticky at the top. The important supplements are high dose B-12, normal doses of the rest of the Bs ( a stress multi vitamin is often good, depending on brand) Omega 3 fish oil, D-3, calcium w/ magnesium, and others on the list as you can.

It takes time but finding the source of your face numbness is important.