What should I do after breaking up to keep myself from being laughed at by my friends?

The most important thing now is to get your predecessor back. Don't be afraid of failure. If you don't have the courage to face this feeling, how can you save it? Everything is changed by our own efforts, so we must cheer up and don't leave any regrets for ourselves.

Never mind that your friends make fun of you. What you care about is your feelings. Do it when you have a definite decision in mind. Nothing else matters. What matters is your own decision.