Hi and welcome to the Chiari forum.
You mentioned you had a cervical spine MRI to rule out a syrinx, BUT a syrinx can form anywhere in the spine so a thoracic and lumbar spine MRI need to be done as well.
Chiari symptoms cycle so they can come and go....and flare so we can have times where we are worse then others.
Most of us can relate to how you feel. as we all have similar symptoms and experiences with this condition as the ones you have mentioned.
Chiari also does not always come alone so you will need to rule out ALL related conditions not just Syringomyelia.....
I had surgery and yes, it did help me.....
I am almost 6.5 yrs post op and would not lift at this point post op as I know it could cause symptoms to return and I was never into lifting b4.
With Chiari most meds do not work....and if you also have EDS it makes using pain meds for surgery difficult too...so make sure you find a true Chiari specialist and rule out ALL related conditions.
Reguarding symptoms,I'm sure everyone is different and symptoms progress at different times.
For me,I was amazed to understand that the changing weather conditions GREATLY EFFECT my symptoms.
Weather changes of any kind ,for me per
Anything that can cause us to strain can cause symptoms to worsen...sorry....but I am sure you will be able to do some sort of lighter lifting once you have healed since it is something your body is accustomed to....but do not try to do it for some time as it could cause you to have set backs post op....and listen to your body as to what and when you can do things.....start slowly and a little at a time....we are all different as to how our body will respond to this surgery.
Also wanted to add that I tried everything Migraine related: medications, Botox, nerve blocks, IV infusion...etc.