The former Love Island contestant, 31, was forced to withdraw from the ITV show after a routine blood test showed she had low sodium and potassium levels, while also flagging anaemia.
Attwood said that when the tests were repeated in hospital, they came back normal, however the decision was made that she would not re-enter the camp.
On landing back in the UK, the TV star had more blood tests, which again came back fine.
In her first TV interview since flying home from Australia, Attwood told This Morning: “I am grateful I’m healthy, but it makes it harder to accept because I’m frustrated because I’m fine. It is what it is. Gutted.”
Attwood said she had been a “big fan” of the show all her life and was looking forward to being the first Love Island contestant to appear.
She said: “Those conversations about the jungle started the first year I left Love Island, it’s been five years in the making for that moment.
“I think when you come off reality shows you get a huge opportunity and I’ve done amazing things.
“But also I think you can be put in a box and I was looking forward to showing a different side to myself.
“I am not a quitter, I am not scared of much and I was loving it and looking forward to having that exposure to a new audience who either don’t know me or think they do but probably don’t know who I really am.”
This morning co-host Holly Willoughby said: “I am so gutted for you.
“When I saw the line-up and I saw your name in there I thought, right here is a girl who is going to go all the way in this because you’re very funny, very brave, strong and I thought this is exactly what we need in that jungle and then 12 days of isolation, going in, jumping out of a plane.”
The reality TV star replied: “What an anti-climax. There’s loads swirling round the internet, I think Olivia Attwood pregnant was trending on Twitter, it’s not that I can assure you.
“I was loving it, I was really in my element and I felt healthy so I was even more confused. It was all really strange.”
When asked how she would have approached former health secretary Matt Hancock entering the camp, Attwood said she’d have used humour.
“I think it’s a difficult one. when you’re living with someone in those environments I think you have to take things kind of carefully,” she said.
“I probably would have done it with humour. I would have given him a bit of stick he deserves although it’s hard even though it is funny a lot of what happened when he was in his position was not funny.
“If you’re someone who lost a relative and didn’t get to say goodbye to them while he’s snogging the face of his secretary whatever, it’s not funny is it but I think I would have gone down that route of trying to have a bit of fun with it. It is a difficult one.”
When asked if she could go back next year, Attwood said it would be a “logistical” thing. She added that she hasn’t been watching the show properly because it makes her feel “sad”.
Attwood added that the winner was a “hard one to call” but hand-picked England footballer Jill Scott and Loose Women presenter Charlene White as potential champions.