£15k budget to travel intermittently throughout the year.

UK, Male, in early 30s. Solo travelling. Never really travelled before. I don't drive.

Can't do hostels. I'm not a partyer, fairly introverted. Need a mix of city and beach life, sightseeing, museums etc and food choice.

I can only do a maximum of one month out of the country before I need to return for medical reasons.

Where I currently do not want to visit(but want to 100% in the future): Vietnam, Cambodia, Japan, South Korea, China, Eastern Europe, France, Germany, Italy, Turkey, Egypt.

My top destinations, including flights, accommodation, food, transport etc:

Thailand - 1 month - £3k-£3.5k

New York - 10 days - £3k

Spain - 14 days - £2k

Greece(Naxos) - 10 days - £1.5k

£5k left, not sure what to do with it. Any suggestions please?