Break-ups are never fun. They can take a toll on your mental health, but eventually, it will pass and you will move on.
Try dealing with the break-up as respectfully as possible. Be civil. It will not help anyone to act out and cause unnecessary, toxic behavior. Quite the opposite, it causes more harm and prolongs the healing process for both of you.
Keep yourself busy by doing more things you enjoy! Find a new hobby, go on a trip with a good friend of yours, even talk it out with your friends and family to let out your emotions in a safe environment.
If truly nothing else helps and you truly can’t get over your ex-partner, you can seek out a therapist to talk through your concerns and questions about the relationship. Venting out on social media is not the best idea, but therapy is a very healthy practice.