Do both.
You are likely to get the biggest bang for your bucks in Thailand, if you like some adventure. You can take land tours and cruises as well when you're in SE Asia. If you do your due diligence, you are likely to be treated like a King in Thailand. Scams and pick pockets abound in that part of the world. The food is very good and inexpensive -- from Asian to European to American/Canadian food. (I was in Bangkok with classmates for an exchange program when I was in grad school -- I had no money to see sex workers then and I had a thing going on with one of my female classmates.
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If you prefer the European ladies, then try Greece. There, you can do a short cruise and then escorted land trips -- and see decent escorts there: supposedly, because of the harsh economic conditions in Greece, sex workers are relatively inexpensive.
Sir Patron is likely to provide your the most useful information about traveling to SE Asia, especially Thailand. There's a nice Netflix show about the food scene in Thailand: it's entitled "Somebody Feed Phil" (season two). The show is about food but it will give you an idea of some of the places in Thailand that you may want to visit.
I once went on a 3-day cruise to Mexico by myself. The cruise ship stopped at several ports where I went horse back riding on a beach and at another port of call, I went jet skiing. Luckily, I ran into a few groups of single folks. For me, 3-days was plenty enough on a ship, especially with kids running around everywhere.
Travel agencies are dinosaurs but they could still help you plan your trips.
Happy Birthday.