Les Price, from Abertillery, Blaenau Gwent, has been told he is not ill enough for weight-loss surgery.
To qualify on the NHS, a person must have a body mass index of more than 35 and a serious health condition which could be improved if they lost weight.
Mr Price, 45, said he cannot complete simple tasks without help.
"It's hard," he told BBC Radio Wales.
"When I have a shower I need my partner to help me wash... and if I need creams put on, then drying and dressing."
Mr Price began to put on weight after losing his wife less than a year after they married.
"It sort of knocked me for six, I didn't want to do nothing," he said.
"It was just takeaways for a good six months. It really hit me hard, so I did overindulge a lot then."
Mr Price also had an accident at work which left him temporarily immobile and unable to exercise, which also caused weight gain.
He told BBC's Jason Mohammad programme his weight attracts attention when he goes out.
"Mentally every time you go out, it's like you're looking at people to see how they are reacting to seeing you.
"Little kids say it how it is, 'oh mam, look at that fat man'."
In a bid to get help, Mr Price met Dr Nadim Haboubi, who runs the only NHS-funded weight management clinic in Wales.
He was initially told he was a "prime example" for a gastric band, but because he does not suffer from a chronic illness which would be improved by weight loss, such as heart disease or diabetes, he does not qualify for the surgery.
"Every time I'm put forward I'm told 'sorry, you're not ill enough'," he said.
Mr Price said he was not "pinning hopes" on the surgery, but accepts his life could be shortened by his weight and has been having injections to reduce his appetite.
He appeared in a Channel 5 documentary about obesity called Fat Chance of Work.
"If I was able to get the operation, I would love to be able to get myself fit enough to go back to work," he said.
"I would love to get back into life and get on living."
A man whose weight ballooned from 23 stone to 35 following the death of his wife has told of his struggles to obtain the treatment he feels he needs.