Fetching details from the dictionary...

rather; sooner; preferably; might as well; just
on the contrary; if anything
こんなに辛いならいっそ辞めてしまいたい。
If it's this hard, I'd rather just quit.
悩むくらいならいっそ素直に言えばいい。
Rather than worry, you should just say it honestly.
いっそのこと最初からやり直すことにした。
I decided to start over from the beginning.