Sepp Blatter has vowed to appeal against his eight-year ban from football to the Court of Arbitration for Sport.
Mr Blatter also insisted he still views himself as Fifa president despite the ban.
Speaking at a news conference in Zurich, Mr Blatter said: "I fight for me and I will fight for Fifa. Suspended for eight years for what?"
Mr Blatter and Uefa president Michel Platini have received the same ban for conflict of interest and disloyalty to Fifa over a two million US dollars (£1.3 million) payment in 2011 based on an oral contract.
Ethics judges ruled Mr Blatter broke Fifa Code of Ethics rules on conflicts of interest, breach of loyalty and offering or receiving gifts.
Both denied wrongdoing when Mr Platini took the payment of Fifa money approved by Mr Blatter as uncontracted salary for work as a presidential adviser from 1999-2002.
Mr Blatter: "I'm sorry as president of Fifa I'm this punching ball."
He had already said he will stand aside in February when a new president is due to be elected. Mr Platini's bid to succeed his former mentor in that election is now likely over, though both are expected to appeal.
Mr Blatter was fined 50,000 Swiss francs (£33,500) and Platini 80,000 Swiss francs (£54,000).
"Neither in his written statement nor in his personal hearing was Mr Blatter able to demonstrate another legal basis for this payment," the judges said.
"By failing to place Fifa's interests first and abstain from doing anything which could be contrary to Fifa's interests, Mr Blatter violated his fiduciary duty to Fifa.
"His (Blatter's) assertion of an oral agreement was determined as not convincing and was rejected by the chamber."
Mr Blatter hit back at that conclusion during his news conference, portraying the ethics committee as saying: "He's a liar and I'm a liar. This is not correct."
He made it clear he regrets his current position, but declared he is innocent of any wrongdoing.
"I regret, but I am not ashamed," he said. "I am sorry that I am a punching ball. I am sorry for football..."
He added: "I will fight. I will fight until the end."
His last words on leaving the conference were: "I'll be back."
Mr Platini later said he too will contest his ban at the Court of Arbitration for Sport.
In statement, he described the Fifa ethics commission's procedure against him as a "true mockery" that had been "orchestrated... by governing bodies that I know well" to tarnish him and Mr Blatter.
Mr Platini, a Fifa vice-president, said his fate had been sealed before a commission hearing on December 18 and that the decision was "just a pathetic manoeuvre to hide a true will of taking me out of the football world".
Along with an appeal to CAS, Mr Platini said he will also file a lawsuit in a civil court to seek damages for what he has endured since the procedure started.
The Frenchman said his "behaviour has always been faultless and I'm at peace with my own conscience".