Hi Olivia
I'm really sorry to hear about your recent diagnosis, but I can offer you hope that this is, for the most part, a very treatable disease. This community is marvellous and is a massive source of strength, support and information to those of us who won this unlucky lottery so keep asking questions.
I was on dasatinib 100mg for several years, and luckily didn't have many side effects, but here are some takeaways that I've learnt on this group and by the comments of others that may help you.
1. More and more evidence is showing that 100mg is way too high a dose of dasatinib to start with. They start younger people on it sometimes because they hope that the drug hits hard and fast, and that you might be one of the lucky ones who are able to come off the medication at some stage in your life. But the downside is that this increases its toxicity. There are a lot of studies that claim that lower doses, such as 70mg or 50mg, are more suitable - dasatinib is known as a "threshold drug" because there is a minimum effective dose and less is more. On this site, scuba and others are experts on this and I'm sure they will weigh in with evidence. In the meantime, do a quick scan of some of the forum posts and you will see their comments! They've even linked some articles from medical journals that you can show your doctor.
2. When we first start on these drugs, our excess blood cells die at a rapid rate. I was told when first diagnosed that this could cause gout / joint pain because of excess acidity in the body and I was put on Allopurinol (brand name is sometimes Puricos or similar). It may well be that this could relieve some of the pain.
3. A diagnosis of chronic myeloid leukaemia is hard on the mind and body. This is a serious condition and the mental toll is quite severe in the early days. It is possible that the fatigue and lack of energy are influenced by the mental and physical stress of the diagnosis and you may well see that this improves over time. You don't mention how "sick" you were when diagnosed (many people feel fine and get the diagnosis on a routine blood test) but in my case I was very, very sick. No energy, bad spleen pain, bruises, night sweats, a popped vein in my retina... I almost had the full Monty! I had a month off work to come to terms with it all, and then saw significant improvements, especially when I saw the numbers going down.
4. An important possible side effect in the early days of treatment is that people become myelosuppressed, i.e. all their blood counts (white, red, and platelets) just crash as the body becomes used to the TKI drug. I am sure your doctor is monitoring these blood counts but, if for example your red blood cells are affected, this reduces the ability of the blood to transport oxygen to your cells, which can cause extreme fatigue. This is usually managed by taking a drug break.
For you the timing isn't great due to the new job, but I have no doubt that as things stabilise you will start feeling better quickly. Best of luck and please reach out if you have other questions.
Best wishes
Martin