Hi and welcome to the travel insurance group
Travel insurance unfortunately, can be more difficult to find reasonably priced travel insurance when you have had a cancer diagnosis and you will find that a Cruise may well carry a higher cost.
Have a look through the Recommended Travel Insurance as it's where we try to keep recommendations from other forum members who have obtained travel insurance? If not, clicking on the link I've created will take you to it and you might find some companies that you haven't tried yet.
Most people recommend that you phone the travel companies rather than try and do online quotes as it's easier to explain to someone than try to do it online.
I do hope that you can get travel insurance for your Baltic Cruise in September.
