Parker feared his international chances had gone after last year's World Cup omission.
"My aim is to be there come this time next year," he said of the prospect of playing at Euro 2012.
"I know there is a long way to go and things can change but if I can help in any way, that is what I will try and do.
"I never felt like quitting England. My mentality was always to work hard and force my way in.
"It was quite difficult not to be selected for the World Cup. After that I thought my chances would have been limited.
"But the Wales game was a massive chance for me. I felt if I didn't perform in that game I would not have pulled on an England shirt again.
"In football, especially at international level, when opportunities come along you have to grab them."