Sorry to hear your news Horseshoes - Cannot be easy having such a diagnosis confirmed, but take support and comfort from family and friends.
From your information, it sounds like it was Essential Thrombocythaemia as a consequence of a misfunctioning JAK2 gene, which accounts for around 50% of the cases.
It is a chronic myeloproliferative disease, but it does tend to develop slowly, and has a minimal impact on lifespan.
One of the things they will be keen to treat is issues around blood clotting, so if you are not already on it, I would imagine they will be prescribing enteric asprin and/or warfarin. in an effort to reduce the risk of blood clots.
And as you say, oral chemotherapy - usually hydroxycarbamide. which generally has side effects that would be classed as mild.
Definitely manageable. Fingers crossed....