Wales entertain Macedonia on Friday at Cardiff City Stadium and are away in Belgium next Tuesday.
"Players come and go and my career has definitely come and gone," Bellamy said.
"I have to do what's best for the national team and this group of players are the future. The next qualifiers, two-odd years, I'm not going to see it."
Bellamy is Wales third most-capped player and is 5th highest goal scorer with 19.
"I'm just grateful for every game I've been lucky enough to play for my country, and I really mean that," Bellamy added.
"It's an honour to play for your country at any level at any sport.
"Playing 70-odd times, it's been the best. Even the disappointments, even the lows, even the times I didn't want to play again because sometimes defeats can do that to you.
"Seventy-odd times having that honour like singing the anthem… it's still the best and Friday will be the best and hopefully I will get the chance to do it again on Tuesday. It will be hard to let go."
Next up for Craig and Wales? Maybe a crack at the managers job?