The 24-year-old was forced to retire from the professional game after suffering a cardiac arrest during an FA Cup match against Tottenham Hotspur last season.
"I never dreamt, not in a million years, that I would be the centre of a story like this," The Bolton News quotes Muamba as saying. "I shouldn't really be here.
"I cannot believe I'm still here. I had always intended on writing a book because I knew my life was interesting. I won't lie and claim that I planned on sorting one out in these circumstances, or so soon."
Muamba, whose heart stopped for 78 minutes after he collapsed on the pitch, married his girlfriend Shauna last month.