Babble by Kelvin V.A Allison

Joe...war hero, heroic vigilante, grieving friend, loving fiance...pathological liar.
Joe however, sees no harm in his ability to babble, effortlessly creating lie after lie to get him through his day to day life, each new lie adding colour to the mythology he has created in place of his real mundane life.
Then his lies start coming true with deadly and devastating results.