Former Chicago Bears quarterback Erik Kramer shot himself Tuesday night in an attempted suicide ... but survived ... and is currently recovering in an L.A. hospital. 

Kramer -- who played 13 seasons in the NFL -- was discovered by law enforcement in a motel in Calabasas around 8 PM, according to NBC. The extent of his injury is unclear.  

The 50-year-old's ex-wife Marshawn told NBC News Kramer has suffered from depression for years ... which she believes is a direct result of the hits he took during his time in the league. 

"He is a very amazing man, a beautiful soul, but he has suffered depression since he was with the Bears. I can promise you he is not the same man I married."

Marshawn and Erik divorced back in 2010 and their 18-year-old son, Griffen, died from a drug overdose the following year.