He wasn't suicidal.
Think about it.
[*]He fights the walkers off. If he truly wanted to die, he would've just let them eat him.
[*]He pushes Lee and locks him out. More than likely because Lee would've wanted to help Ben and wouldn't have opted to mercy kill Ben (due to all the Ben lovers on here).
[*]Further evidence of this is the fact he backs away from the horde, the opposite of Lee's death march to the Marsh House.
[*]In the Christa version he starts to say something like "Go! I'll me--" Like "Go, I'll meet you somewhere" possibly.
Not saying he isn't dead. Just saying he wasn't suicidal.