Hilo and welcome to the forums. It can be rough getting to day 100, but fear not, you can do it! If you are playing solo, maybe you could invite friends to join you. It is always more fun with others you know in game.
Hilo! It can definitely get tiring to grind out survival days but you're already half way there!! Also there's a survival mode overhaul just around the corner, so even if you can't get the motivation right now I'm sure you can try again by the time the update arrives!