Jack Leach says he "uses the lows to propel me on to the highs" after his five-wicket haul left England on the verge of victory over Sri Lanka.
Despite falling to 38-3, England need just 36 runs to win the first Test in Galle after Leach's 5-122 helped them dismiss Sri Lanka earlier on day four.
The spinner is playing his first Test since November 2019 after a run of health issues saw him lose his place in the team.
"The last 12 months haven't been ideal but it's good to get out there," Leach, 29, said.
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"I try and use those lows to propel me onto the highs and it puts a bit of perspective on things as well.
"If I am healthy, fit and able to play that is a very great thing and I don't take that for granted."
Leach, who has Crohn's disease, contracted sepsis on England's tour of New Zealand in 2019. He flew home from the tour of South Africa two months later when he was unable to regain fitness, after also suffering from gastroenteritis and flu.
He was in England's Test squads for much of last summer, inside the bio-secure bubble, but did not play a Test with Dom Bess preferred as spinner.
He became a cult hero for his role alongside Ben Stokes in England's Ashes third Test win at Headingley in 2019 but two appearances in the Bob Willis Trophy for Somerset were his only matches in 2020.
"That period in South Africa was probably the toughest," Leach said.
"After being ill in New Zealand, feeling like I had got myself back for the South Africa tour, picking up more illness in South Africa - I found that a tough experience."
Leach's five-wicket haul in Sri Lanka's second innings of 359 was his second in Tests and followed figures of 1-55 in the first innings.
Although his former Somerset room-mate Bess took 5-30 on day one, England's spinners were criticised for their performance in the opening part of the match.
"Today it is nice to have five wickets but I understand at times I didn't bowl as well as I would like," Leach said.
"I bowled better as the game has gone on which is a good sign."
Former England captain Michael Vaughan, who highlighted England's spinners as a weakness after day three, said he was "delighted" for Leach and agreed he had improved on day four.
"Everyone around the game in England knows what a good guy he is," Vaughan told BBC Test Match Special.
"Not just that innings at Headingley - that puts you into cricketing royalty when you do things like that that.
"He bowled 41 overs in the second innings and did get better and better.
"He bowled some batsmen out with good deliveries. That holds England in good stead for the next game."
Follow day five of the first Test on BBC Sport website and BBC Radio 5 Live Sports Extra from 04:15 GMT on Monday.
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