How on earth did you find this thread lmao? One of the comments is talking about mana pots.
Anyway, the thing with the soraka matchup is that while on paper you have the tools to win, you dont have enough of any particular one of them. During laning phase you don't have the damage to actually kill her in one trade, and the longer a trade goes the worse it gets for naut because his W and Q are on such a high cd. So you trade with a soraka, and she just walks away and heals up, so that a minute later enemy botlane is full hp and yours isn't because you were trading. To get through that, you basically need to get a good trade off, wait for cooldowns without raka landing a Q, and then get another nice engage and finish a kill. Otherwise you just slowly lose.
Also, her E can deny your trading if used correctly (rare that I see this done but still). And in some matchups she can just sit back and spam heals as her adc kills yours, since if it's something like Ezreal, Naut doesn't actually have much of a deterrent to him just blinking in and 1v2ing (slows do nothing if he's already in range, all you have is Q and Exhaust for cc).
Ignite is a thing, but it's not a sure victory and giving up exhaust hurts.
All that said, this matchup also depends on the patch. The OP was back when her Q and W heals were instant. If Raka is weak numerically, you can faceroll her.