I think BBC4 did a documentary on him a while back.
Basically what happened is that after Catchphrase ended, he tried to take his act on tour at various holiday resorts, initially with Roy Walker but they later had a falling out which meant that no one could say "Say what you see!" and the entire show died there.
After that he got various odd jobs, some advert work, he was shortlisted for a I'm A Celebrity, Get Me Out of Here! but was considered "too obscure". Eventually, after a series of drug problems, he decided to end his life. The only clothing he hadn't sold for drugs money was an old racehorse outfit from his Catchphrase days. Putting that on, with a tear in his eye, he put out a short "This is the end of my life" tweet to his four followers, got on his kitchen table, put a noose around his neck, and stepped off.
The police eventually arrived days later, knocking down his locked door and rushing into his dining room to see the sight before them, whereby they instantly said "Is it... 'Hung Like a Horse'?".