If you can go, I would recommend to do it. But go in the summer, not now. Now is the moment to stay here, good weather and all. If you went now you would hate yourself after two days. I was trapped here last summer (I always go to my country in the summer) and was hard. But this year went and stayed longer than usual. Your mental health will appreciate and you will come back with renewed energy. For me going back once a year (summer) is a must.
As for health insurance, I am younger, so I don't know how this can apply to your case, but I have been using AETNA (previously BUPA) and they always paid what they owe. I was one time hospitalized for 3 days and when the bill came I was relieved to see I had to pay nearly nothing. I think the most tricky part in Thailand is choosing the right hospital (avoid blood suckers such as Bumrudwhatever and so on) rather than on the health insurance itself.
While you don't go to the UK yet, I do think it helps to travel in country, even to the next province, for a break.
Good luck.
