You don't say how long you are travelling for, nor what you intend to do in Thailand eg mountain trekking above 2000m (unusual, if not impossible in Thailand - I haven't checked a topological map recently), SCUBA diving etc, plus wanting cover for expensive camera or other electronic equipment can all push up the premiums. Annual cover may not be appropriate for trips longer than their time limit, of say 30 days for each trip. Some activities eg moped riding, may be excluded completely, and people have found their insurance companies refused to pay out after they had moped accidents. One tip than can help you to save money is to find a company that offers "worldwide, excluding USA", as it's the USA bit that ups the cost, dueto their health system, rather than the entire world.
The only horror is if what you (with diabetes, assuming no other problems eg asthma, nor complications, nor recent hospitalisation for diabetes) were quoted a higher amount to your boyfriend, assuming he doesn't have any long standing health issues? If you live together, then travel insurance for a couple is often less than double for an individual. To be honest, ?67 doesn't sound too bad for, say 1 month.
But worth checking the aspects I have mentioned - and have a great trip, with adequate insurance cover.