Welcome Robin, It's pretty common to still have side effects at this early stage, but let the doctors know for a proper evaluation, and to rule out other possibilities, and treatment for such things as mucocitis, dry mourh, thrush or any bacterial or viral infection, nutrional counseling, etc. if needed, and probably is. I felt best around 3 months in some aspects, 6 months, a year and so on in intervals, and can take up to two years to recover, sometimes longer. I'm still recovering 4.5 years later. It's a marathon for sure, but things do get better, but not overnight.
Maybe try smart water, and avoid foods that are acidic, spicy, too hot, sharp textured as not to irritate the mouth, and eat softer foods. Sugar and milk even burned my mouth.
Good luck, and if you have any questions, ask.