Paul Colling, 34, who served in Afghanistan and Iraq, was a Corporal in the Royal Corps of Signals before a training exercise injury to his ankle brought his career to an end in 2007.
He said he felt like his world “had ended” when he left the forces and – despite finding new employment – struggled without his military identity.
Mr Colling said charity Help For Heroes helped him throughout some “dark times” in the years that followed,giving him mental health support and counselling.
He said he wanted to “give back” this VE Day and is raising money through his biggest hobby – playing video games.
For 24 hours he will take part in Hero Up – an initiative where people can fundraise for the charity by playing and streaming games online.
All donations support individuals affected by their military service and their families.
He said: “Gaming has kept me sane, but the reality is Help for Heroes stepped in to help save my life. I was in some dark places when I left the military, tried some very silly things a few times, but engaging with Help for Heroes gave me the ability to be honest with myself and people around me.”
He said he hoped the initiative would help engage a younger audience and show how younger veterans were adapting to life outside the army.
To donate, go to http://givepenny.com/paulcolling_hero_up_twitch