Hi and welcome to the Chiari forum.
your English is well enough, I feel I understand your questions....hopefully you can understand my reply.
First, it is not how long the tonsils are but rather if they are obstructing CSF flow.....it is possible for them to be long and thin and it could cause no issues and you could have much shorter ones that are stoudt and cork up the flow....DO your research....Chiari does not = surgery as it is only done to restore CSF flow...if there is no obstruction, there is no need for surgery.
Symptoms you have may be due to other comorbid conditions...AND Chiari symptoms cycle....so itis possible to also have some symptoms flare after an illness or stressful time...and it could also go away for a time.
As for recovery should you be deemed a surgical candidate, we are all different in how we heal, handle pain....and what else is going on with our health....that all bears into how we recover.