As seamus said. Sackings aren't bad. Sackings are part of the LLM-Experience and without them the game wouldn't be any fun. There are even people here who always try to get relegated and sacked (LFCFan) because they enjoy it above all.
As for not finding a new job. You can either go on holiday, and have yourself apply for any vacant jobs. You can start a new game. If it's a long-term game and you don't want to give it up, you could even retire and add a new manager (dirty). It's up to you. I prefer waiting for a new job, and if I don't find one after a whole year, I start a new game.