I’m sorry that you’re in more pain, as @Isaiah_40_31 says the recovery from ES surgery definitely has ups & downs, steps forward & then back, so this certainly isn’t unusual…
Here’s a link to a recent discussion so you know that you’re not alone:
Post Surgery Headaches After (1) Month - General - Living with Eagle
If you can delay going back to work that would be helpful… I hope that Mr Axon has some suggestions to help you , and try to focus on what has improved 
