If you mess up the tame and get bucked off, when you get back on the taming process becomes harder and requires more carrots. The more times you fall, harder it gets. Get a tribe mate to cover you while taming to keep troodons and the like at bay.
(For Ark Mobile players) - you do NOT have to mount the Equus to complete the “Tame Equus” mission [I hope someone’s stress levels went down upon hearing that]. It seems to enjoy spawning near annoyingly dangerous dinos. Feed it rockarrots and MOVE AWAY until it is hungry again. Follow those two steps until you tame it. For me it took 8-10 feeds, lasted 7-9 minutes. I was lucky that the T-Rex, Raptors and Carnos got themselves killed AND my Equus (Willa) glitched between trees making taming easier. I hope your tame goes just as smooth. Good luck friends :)