I tend to put Ohio State losses into three categories, two of which are easier to get over and a third that is the hardest:
1. Games where Ohio State played poorly and lost - e.g. 2018 Purdue, 2017 Iowa. These are hard to swallow knowing they're games Ohio State would normally win. But when you play terribly, like they did in these games, you shouldn't expect to win.
2. Games where Ohio State played well and still lost to a team that was just better on that day - e.g. most of the 2011 losses, 2014 Orange Bowl. There aren't a lot of games over the past 10 years where Ohio State has played well and been on the wrong side at the end. It obviously sucks to lose these games, but when you play well and fight and just lose to a team that was better on that day it's easier to get over.
3. Games where Ohio State was clearly the better team, and either from unforced errors or just bad luck they lose - e.g. 2015 Michigan State, 2019 Fiesta Bowl. These are the hardest to get over, because you can replay so many scenarios in your head - a right call here or catch there and the entire outcome changes. The 2015 game at least had a successful end with wins of TTUN and a win in the Fiesta Bowl, but still knowing how talented that team was it made it harder to get over.
I'd argue this 2019 loss to Clemson will be the hardest I can remember - we had a talented team comparable to the 2015 squad, played well during the majority of the game, but because of a number of reasons that I won't rehash here still lost. With no games after it to help it makes it sting that much more...