The former Germany international made the announcement earlier this season.
He told Villa's website: "I loved playing for Villa. I loved the roar of the Holte End and the support from all around the ground. It was a brilliant place to play football.
"I played football for the fans. I wanted to make them proud.
"I know Villa fans - all they ever want from one of their players is effort, hard work and a willingness to give absolutely everything for the shirt.
"I believe that sexual orientation doesn't matter to them. Their support is unequivocal.
"Since I made the announcement, I have some really great reactions from Villa fans and supporters from all the other clubs I played for - and fans from clubs I didn't play for too.
"They told me in these messages, from sites like Twitter, that they cared for me as a player and all they were interested in was a good performance on matchday.
"Some said it was brave for me to come out. Others told me they have more respect for me now.
"I haven't had one nasty comment from fans - and that means a lot."