Detective Sergeant Nick Bailey requested privacy for his family in a statement after leaving hospital for the first time since the 4 March attack.
He said his “life will never be the same again” following the Salisbury attack.
“People ask me how I am feeling, but there are really no words to explain how I feel right now,” he said.
“Surreal is the word that keeps cropping up and it really has been completely surreal.
“I have been so very overwhelmed by the support, cards and messages I have received. Everyone has been so incredible.
“Some days we’ve had about 300 messages from officers, the wider police family and the public. The level of support has been unbelievable and I’ve tried to respond to what I can, but I want to say I have really appreciated every single message.
“One thing that has lifted me throughout the last few weeks has been the public support the police service has received during this incident.
“All the stories of community spirit, from the local businesses providing food and hot drinks to the officers standing for endless hours on the cordons, to the members of the public just showing their support for our work - have been quite simply overwhelming to hear about.
“I want to pay tribute and give my absolute and heartfelt thanks to the staff of Salisbury District Hospital. The care I have received from the medical staff has been simply outstanding from day one – from the man that cleans the floor to the doctors giving the treatment. They have all been absolutely phenomenal. Thank you just doesn’t seem enough and just doesn’t convey the gratitude I feel for what they have done for me.
“I have spent all my time since the incident really focusing on trying to get better and trying not to think about anything else.
“But as I have begun to feel better, I have become aware of the widespread and enormous attention this whole incident has attracted.
“I find this really overwhelming. I am just a normal person with a normal life, and I don’t want my wife, children, family or I to be part of that attention. I do hope the public can understand that.”
His discharge came as Theresa May presses for a united statement from the European Union condemning Russia for the nerve agent attack in Salisbury.
Foreign ministers of the 28-nation bloc issued a statement on Monday voicing “unqualified solidarity” with the UK.
However, they stopped short of pointing the finger of blame at Moscow for the 4 March attack on ex-spy Sergei Skripal and his daughter Yulia.
Arriving in Brussels today for a summit of the European Council, Mrs May said she would brief fellow leaders on the “brazen and reckless” use of chemical weapons on European soil and leave no doubt she sees it as part of a pattern of Russian aggression that requires a united response.
Britain has been pressing EU allies behind the scenes to follow its expulsion of 23 “undeclared intelligence officers” from Russia’s embassy in London by sending home Moscow’s spies in their own countries.
Mrs May is set to address the other 27 EU leaders over dinner on her belief Europe faces a challenge from Russia that will last many years and represents a threat to the continent’s democracy.
Wearing a white ribbon in commemoration of terror attacks in Westminster and Brussels, the Prime Minister said: “Russia staged a brazen and reckless attack against the United Kingdom when it attempted the murder of two people in the streets of Salisbury.
“I will be raising this issue with my counterparts today because it is clear that the Russian threat doesn’t respect borders and indeed the incident in Salisbury was part of a pattern of Russian aggression against Europe and its near neighbours from the western Balkans to the Middle East.”
Meanwhile, in London, Russia’s ambassador Alexander Yakovenko condemned Foreign Secretary Boris Johnson’s comparison between Mr Putin hosting this summer’s World Cup with Hitler’s 1936 Olympics as an “insult” to the Russian people.
Mr Yakovenko demanded evidence for Britain’s allegation Russia was behind the Salisbury attack, saying official statements on the poisoning had been “wild” and the UK had “built its official position on pure assumptions”.
At a press conference at his London residence, not far from Kensington Palace, he said: “We demand full transparency of the investigation and full cooperation with Russia and with the OPCW (Organisation for the Prohibition of Chemical Weapons).”
Mr Johnson had escalated the war of words with Moscow by suggesting Vladimir Putin was hoping for a propaganda boost from this summer’s World Cup similar to that which Hitler sought in the 1936 Berlin Olympics.
Mr Yakovenko condemned the comments, saying: “Nobody has the right to insult the Russian people, who defeated Nazism.”
He said the comparison “goes beyond common sense”.
Mr Yakovenko added the response of the Government and various statements since the incident had created “serious problems” in the Russia-UK relationship.
He said: “What really worries me is that the way this campaign is being presented is very anti-Russian. It really creates serious problems for the UK itself.
“Because after two weeks of this kind of really wild statements, how are you going to talk to the Russians?
“Because as I said that was really very insulting to the Russian people. It’s not about government, we’re talking about people.”