It's way too early in the morning for me to wrap my brain around the idea of a future version of myself... 
The Flash (Volume 4) #35 is an issue of the series The Flash (Volume 4) with a cover date of December, 2014. It was published on October 22, 2014.
Synopsis for "Out of Time"
The Flash of twenty years in the future has finally gone back in time far enough to fix the damage to the Speed Force. Meanwhile, the present day's Barry Allen is just waking up and eating breakfast when his future self yanks him off his feet and carries him all the way to the Utah salt flats, where Daniel West crashed out of the Mirror World when he became the Reverse-Flash. His future self explains that when Dr. Elias' Speed Force charged monorail crashed in the salt flats, it broke the Speed Force, and Daniel used the hole to travel into the past. As a result of both his and Barry's travels back in time, Barry has begun losing time. Eventually, he'll start missing things that he should have been there to stop - things that will kill the people he cares about. Wally West will be among them.
The Flash of the future explains that he has gone back in time to fix every instance where his past self was too late to stop something like that from happening, and now there remains only one thing left to fix: the Speed Force tear. His plan for repairing it, though, involves sacrificing the present day Barry Allen to fill the hole with his Speed Force energy. In dying, Barry will release that energy. Barry has little chance of winning in a fight, because his future self has already trained with the masters of martial arts.
Barry reminds that if he dies, the future version of him won't exist anymore. Future Flash responds that changing the present will change the future, but he's not in the future anymore. The Speed Force rupture cannot simply be undone, it has to be closed, which is why Barry has to die. In response, Barry dons his costume, and faces his foe at full speed. Unfortunately, speed is all he's got, and he's no match for his opponent. As he struggles in the grip of his future self, the Speed Force begins trying to repel them, because two of the same person aren't supposed to be in the same place at the same time. The future Flash hopes that by charging that repelling force, it will add to the power he will have to close the rupture. Suddenly, though, the pair are torn apart from one another by a third speedster: Wally West.
Wally the future Flash of going about things all wrong. He spent years training to come back in time and to prevent Barry's future self from going back in time any further and doing more damage than he did when they last met. Angrily, the future Flash attempts to kill Barry by flinging high-speed rocks at him, prompting Wally to leap into their path. Injured badly, Wally crawls to Barry's side as the Speed Force energy is tearing him apart, and explains that he can absorb the excess energy to save him. As he begins to recover, Barry realizes that his savior is Wally West, just in time to hear the young man beg him not to give up on him. He had only learned to become a hero because of Barry's influence. As he dies, Wally releases a blast of Speed Force energy that closes the rupture, leaving the regretful future Barry Allen alone in the salt flats with no way back to his own time.
The present Flash, though, is anywhere but the present, finding himself in a jungle where he is soon under pursuit by a dinosaur. Unfortunately, his speed is gone. What's weirder is that he is saved by what appears to be a robotic drone, who declares that he should be exterminated as well.
Appearing in "Out of Time"
Featured Characters:
Supporting Characters:
- The Flash (Wally West) (Dies)
Antagonists:
Other Characters:
- Dinosaurs
- Patty Spivot
- Batman (Mentioned only)
- Darwin Elias (Mentioned only)
- Deathstroke (Mentioned only)
- Grodd (Mentioned only)
- Lady Shiva (Mentioned only)
- Overload (Mentioned only)
- Reverse-Flash (Mentioned only)
Locations:
Concepts:
Items:
Vehicles:
Notes
- This issue is reprinted in The Flash: Out of Time.