3 weeks recoup is still going to be difficult, I will urge you to not take the cottage because the benefits of the dusit outweigh it considerably, about 90% of Doc C's stay at the dusit so you wont be alone, and making friends is terrific and helpful in recovery, another thing is the mall is literally next door! and you can get everything there. also free fast wifi is at the dusit, and the hotel staf are very curtious and super helpful.
its possible to go see things in Thailand before you leave, but you must be careful, I was going to the mall in the 2nd week, and there were lots of spots I could sit and catch my breath there, also so many food options, 2 supermarkets, lots of pharmacies the mall is insanely huge!
you will lose 10 lbs easy during just the surgery and recoup time!!!! so don't worry so much on dieting as your body is going to need everything you can give it! Oh and also invest in vitamins, such as B-comlex, D and omega 3-6-9 complex it will help recovery.
Don't buy bread products to store for later either shelf life is bout 3 days there as they don't use preservative!
what I did at the hotel is I would get breakfast and stock op extra for later or to snack, than get something for dinner, I never ate at kfc, or mcd's but I did eat at subway and a Korean buffet, with other patients which was awesome!!! 8 bucks each for 4 and you got unlimited food!!!!
so I hope this helps imo there is no comparison between the dusit and the cottage .