I been having system overloading on Logic pro X so I bounced all my tracks individually to mp3 and re added them to new project is that bad?

Answer 1

mp3 compresses files. if you output them again, they will be recompressed, which is bad.

next time, output to WAV files.

Answer 2

Using MP3 format is bad, as MP3 uses lossy compression.

You should use .WAV or a similar uncompressed format.

That will also reduce CPU load as there is no decompression, it's just straight audio data.