Sandra,
I found the first six months after diagnosis to be quite challenging.The bone pain led to some sleepless nights but as one medic said to me the drug is doing its job and your bone marrow is changing and the leukaemic cells are reducing-so a positive is happening.Hopefully you are responding well to treatment and that the cytogenetics are going in the right direction.
Fatigue is a normal side effect of a tki like imatinib or as well it could be partly a result of the disease itself.I had lots of eye pains and eye bleeds as as time went on these reduced;it might be an idea when it is possible to have your eye pressures taken as the drug can lead to the optic nerve being affected.The mood swings and anxiety I found hard to deal with but these are listed in the side effects.Headaches might be related to how and when you take the pill as taking it without adequate water and food can contribute to nausea and headaches.
I suggest that if you are responding well then try to stick with it for a while and hopefully things will get better as the drug and the body get used to each other;perhaps if the chills become very concerning then that is the time to seek help.
The alternative tki s might seem attractive as a possibility but remember one in five who take dasatinib suffer pleural effusions and with nilotinib there is the need to fast before and after taking the medication and it can be tough on the heart.
After 14 years on imatinib I still get dreadful muscular issues and cramp at night but the drug has the right effect still so we have to carry on .All tkis will have some side effects and hopefully one hopes that the ones that affect you are not too severe.
With best wishes
John