The troubled actor was sacked from Two And A Half Men earlier this week and lost temporary custody of his two-year-old twin boys to ex-wife Brooke Mueller last week.
In an interview with Life & Style, the outspoken star said that he is struggling to keep his life together.
'I'm really starting to lose my mind. I'm ready to call anyone to help,' he said. 'I'm really trying to contain myself right now. My lawyer wants to come over to my house and take the bullets out of my gun.'
Talking about his kids, he added, 'She can't keep them from me. I won't let her! I'll do anything to get them back.'
A source told the magazine that Sheen's erratic behaviour is worrying everyone who knows him. 'It's crazy over here at the house. Charlie's losing it. He's really mad about the show, and dealing with the kids and Brooke is getting to be too much.
'Charlie is a ticking time bomb, and we all fear he could do something drastic like committing suicide or falling back on hard drugs.'
A second insider added, 'Anything could happen at any minute. He's a danger to himself... a really big danger.'