I second what u/AgencySilver1019 said. Seeking vestibular physical therapy from a physical therapist should be your first step, because it can help with dizziness, and the dizziness is likely contributing to the headaches, brain fog, and anxiety. Depending on your health insurance situation, you can usually (but not always) get this covered if you tell your primary doctor you have post-concussion syndrome and ask very specifically for a referral to a physical therapist for vestibular physical therapy. Do that first, and then see what symptoms remain.

In the meantime, try sleeping on a wedge pillow. It can't hurt! https://www.amazon.com/HEALTHEX-Bed-Wedge-Pillow-Heartburn/dp/B0979K84JJ/ref=sr_1_5?dchild=1&keywords=wedge+pillow&qid=1632846299&sr=8-5

I didn't have headaches, bizarrely, but for those I think it's important to do one of the simplest things: HYDRATE! Your brain floats in a protective layer of water inside your skull, and it really hurts when the layer gets too thin, especially when the brain is injured and recovering.

Soccer season is a good motivation to work hard on your recovery, but if you aren't ready in time, please don't beat yourself up. Find the activities that you can enjoy right now, like walks, or going to the gym to lift weights. You're not alone and you will get better.