Will Allah punish me or take revenge on me by sending me a bad suitor because I was previously involved with someone without everyone's knowledge?

The engagement does not permit the suitor anything beyond looking at his fiancée. His ruling remains that of a stranger until the marriage contract is concluded. Therefore, it is not permissible to converse with the fiancée without a recognized need. This also applies to non-suitors, whether with or without the family's knowledge. You must repent to Allah from this relationship by abandoning it, feeling remorse, and resolving not to return to it. Sincere repentance erases what came before it, and one who repents from a sin is like one who has no sin. The repentant person is not punished for their sin in this world or the Hereafter.