The 31-year-old, capped more than 50 times for Germany, announced he was gay this week, the first high-profile German player to do so and the first to have played regularly in the English Premier League.
In an interview on the BBC's Football Focus, Hitzlsperger said the past few days had been "intense".
"I've been overwhelmed by the response," he said.
"It's all been very positive and it was quite intense too. I knew it could be big news, but after a couple of days I realised it was big news.
"I asked friends a couple of years ago about going public but they just told me to keep my head down and play football so I've waited until now to reveal it."
Hitzlsperger, once known for his powerful free kicks, said he hoped one day players would feel comfortable about coming out as gay while still playing.
"The more professional athletes talk about their sexuality the better," he said. "There isn't a gay footballer currently playing so it's harder for the governing bodies to deal with it.
"I assume they will wait for someone to come out and they will react to it."
Despite soccer's global popularity, the sport has seen very few gay players come out, especially during their active careers as the fear of a negative reaction from coaches, team mates and fans forces them to keep their sexuality secret.
Britain's most famous case was that of former Norwich City striker Justin Fashanu, who came out in a tabloid newspaper in 1990 and committed suicide eight years later.
Former Leeds United player Robbie Rogers quit soccer and came out as gay after being released by the Yorkshire club last year.
The American's decision to restart his career at Los Angeles Galaxy prompted the New York Times to dub him "the first openly gay man to participate in a prominent North American pro league" when he made his debut against the Columbus Crew in May.