BEIJING, Dec. 17 -- Sun Yang received a gift for his 22nd birthday from Swimming World Magazine on December 1 - he was elected as the Male World Swimmer of Year 2013.

Instead of celebrating, he apologized - for an eventful year that saw him breaking up with his coach, missing training and caught driving without a license.

"I am deeply suffering from guilt, apology and regret towards my parents, coaches, supporters and friends," said China's first ever male Olympic champion swimmer on his Twitter-like Weibo account.

"I have grown up and matured. I will work harder, discipline myself and correct my mistakes.

Sun was detained by police for driving without a license in a car accident in Hangzhou in November and has been suspended from the national team since.

Earlier in the year, Sun reportedly had a strained relationship with his long-time mentor Zhu Zhigen while struggling to balance his romance and career.

The two later reconciled, but Sun was left in Hangzhou alone while Zhu led other swimmers to Yunnan in April to prepare for the world championships in Barcelona.

When Zhu's team moved to Beijing in June to get ready for the world championships, Sun wasn't seen training with his teammates.

For about two months, Sun had been training alone, without a coach to give advice or a teammate to compete against.

Sun vowed to sweep his specialty events before leaving for Barcelona, and he did.

With the world titles in the 400, 800 and 1,500 meters freestyle, Sun became the first ever Chinese to be named world best male swimmer by world swimming body FINA in August.

"I just experienced a very difficult time in my career. I hope to use gold medals to prove myself and clear the doubts," Sun said emotionally after winning 400m in Barcelona.

In September, Sun went on to bag five gold medals in the National Games and broke the 200m freestyle Asian record.

When things seem back to normal, Sun was in trouble again.

On November 3, a Cayenne driven by Sun Yang was rear-ended by a bus. When police arrived at the scene, it was found that the swimmer was behind the wheels without a license.

Zhejiang College of Sports, to which the swimmer affiliated to, later disclosed that "Sun refused to return to the team after holiday and he was unreachable until the accident took place". The college also said Sun even traveled to Thailand without team approval.

"I am deeply sorry for what I have done and will reflect on my behavior," Sun apologized on Weibo on Nov. 4.

Sun was suspended from all competitions, national team training and commercial activities.

Sun was also excluded from the "best male athlete" voting in prestigious China's Central Television (CCTV) Sports Awards.

"Sun Yang is an outstanding athlete but he failed to behave professionally outside the swimming pool," said CCTV sports chief Jiang Heping, "Most selectors on the panel decided not to accept him as a candidate."

As the most successful Chinese athlete for the year, Sun Yang won't stay in exile for long.

"We need to watch Sun Yang for a while. If he behaves well, it may not take long to allow him back to the national team," said Shang Xiutang, a top Chinese swimming official.