Lewis Capaldi has released a rousing comeback single about his determination to overcome his personal struggles after two years out of the public eye.

The Scottish singer is also heavily rumoured to be making an unannounced appearance at Glastonbury on Friday, two years after an emotional performance when festival fans lent their vocal support as his voice faltered.

He then retreated from the spotlight to get his “physical and mental health in order” and “adjust to the impact” of a Tourette’s diagnosis.

He addressed his private battles on the gutsy Survive, which was released at midnight, and which opens with the line: “How long ’til it feels / Like the wound’s finally starting to heal?”

The lyrics go on: “Most nights I fear / That I’m not enough / I’ve had my share of Monday mornings when I can’t get up.”

The lines “But when hope is lost / And I come undone” then lead into the deliberately contradictary chorus: “I swear to God I’ll survive / If it kills me to / I’m gonna get up and try / If it’s the last thing I do.”

In the song, the 28-year-old also defiantly sings that he refuses “to spend my best years rotting in the sun” and is determined “to get up and live / Until the day that I die”.

The release coincided with a message on Instagram saying “It’s been a while…” accompanied by a video montage of clips from his career.

“Welcome back brother,” wrote fellow singer Tom Grennan on Instagram.

One fan added: “I didn’t plan on starting my day with tears, but wow, your lyrics never disappoint. Incredibly happy you are ready to be back for a bit.”

Survive is Capaldi’s first new material since his second album was released in 2023.

Both of his albums went to number one in the UK, and his 2018 single Someone You Loved topped charts around the world and is now the fourth most streamed song of all time, with almost four billion listens on Spotify.

But he also spoke openly about the pressures of touring on his mental and physical health, and about the impact of panic attacks and Tourette’s, which he was diagnosed with in 2022.

While performing on Glastonbury’s main Pyramid Stage in 2023, vocal problems left him almost unable to sing his final songs.

As his band played Someone You Loved, the singer largely stayed silent, with the crowd belting out the words and carrying him along on an affectionate wave of support.

“It was a wonderful, communal display of both the Glastonbury spirit, and the genuine public affection for Capaldi,” BBC music correspondent Mark Savage wrote at the time.

Days later, he cancelled all concerts “for the foreseeable future”, saying he was “still learning to adjust to the impact of my Tourette’s”, and needed time to work on his health “so I can keep doing everything I love for a long time to come”.

In an update on New Year’s Eve 2023, he told fans he had “noticed a marked improvement” in both his Tourette’s and anxiety issues, but wanted to “make absolutely sure I’m 100% before getting back out there again properly for more shows”.

He made a low-key comeback at a benefit gig for the Campaign Against Living Miserably (Calm) mental health charity in Edinburgh this May.

Glastonbury will be his first high-profile appearance, if he does – as widely expected – fill the “TBA” slot on the Pyramid Stage at 16:55 BST on Friday.

If that is the case, he will undoubtedly be met by huge support from the festival crowd.

Posters for a Lewis Capaldi lookalike contest to take place 10 minutes before that slot have also appeared on the site.