“Hi everyone, it’s Stephen here – still here and still fighting!!!” he wrote.
“Throughout the whole journey I’ve been realistic about my position and at my last post I genuinely thought I was a goner…. But hey, I’m still here!!
“Sunday morning my right lung collapsed: I had a full emergency team surrounding me and in all honesty was probably not too far from nearly leaving you all.
“I survived, but the following day I woke up and felt very weak – the worry was that whatever was left of my health would just continue to deteriorate.
“However, from that point on my recovery has been positive and quite unexpected.
“One doctor while seeing me even said how my medical notes and how I was actually doing didn’t quite seem to match up.
“The progress since has continued to be good but steady.
“I am still in a very vulnerable position.
“I am very limited in what I can do and am still permanently hooked up to oxygen.
“But I am in high spirits and blessed to have so much love and support around me.
“To get to see the million pound fund-raising target being reached was just phenomenal!”
Mr Sutton, from Burntwood, Staffordshire, added that he planned to take things day by day “but I am happy – and that’s the main thing!”
A host of celebrities have taken to Twitter to help the cause, posing for pictures with the hashtag thumbsupforstephen and holding signs urging the public to donate.
The teenager was diagnosed with what was initially bowel cancer, when he was 15.
Despite surgery, the aggressive cancer spread to different parts of his body and, after further treatment and operations, doctors concluded it was incurable.
Fighting the disease, Mr Sutton decided to set up a bucket-list of 46 things to do before he dies along with the fundraising campaign, setting an initial target of £10,000 before it was smashed by the huge number of public donations as publicity around his cause spread.
The campaign is also being backed by comedian Jason Manford, who said he had previously met the teenager at charity gigs.
Appearing on ITV’s Daybreak, Manford said he and others were inspired to get involved by the teenager’s positive attitude as he strove to make the best of his situation.
He said: “That’s what got their imaginations going really. It was that he just had such joy for life.
“He wasn’t bitter about leaving the party early, he was just happy that he was ever invited at all. He’s 19, which is no age at all.
“There’s so many things he’s not going to be able to do, but there’s something he said on his Facebook page and on his website – he said that life shouldn’t be measured in time, it should be measured in achievements you’ve accomplished and I thought ‘This guy’s 19’, and it really got to me.”
Mr Sutton set up his charity fund-raising website and blog on Facebook in January last year to keep people up to date with his progress.
On Tuesday he wrote that his condition had worsened, adding “unfortunately I haven’t got much time left”.
Thanking family, friends and fundraisers, he said: “That’s it from me. But life has been good. Very good.”
Siobhan Dunn, chief executive of the Teenage Cancer trust, praised the inspiring teenager and ambassador for the charity.
She said: “I’ve had the privilege of meeting him and his positivity is always remembered by all that meet him or hear him speak.
“Stephen is making the biggest possible difference to Teenage Cancer Trust and the young people who need our help.”
Speaking previously, Mr Sutton said he disliked the term “dying from my cancer – I am living with my cancer, despite it being there”.
His bucket-list included things like hugging an elephant, crowd-surfing in a rubber dinghy, playing the drums at a Wembley cup final, getting a tattoo and appearing on BBC drama Doctors.
Manford tweeted a picture of himself visiting Mr Sutton in hospital yesterday.
He wrote on Twitter: “Amazing @-StephensStory is up & chatting after his brush with death. He’s so happy that we are close to £2million!”