Does he deserve a second chance?

I made a dumb decision by reaching back out to my ex after breaking up. We talked through the reasons why I decided to end things and he seems like he understands.

He says he seriously wants to change after having a VERY in depth conversation. Before when I would get mad/ upset with him we’d just yell/ argue. He wants me to give him another chance. I really like him but it’s only be 4 months of us dating and we’ve been arguing so it seems pointless.

My best friend told me she thinks it’s a stupid decision to get back with him and that she thinks I’ll regret it later. She said she thinks if he and I got married we’d file for divorce after five months.

I told him we need space to reflect and for him to truly make changes/ process the things I told him but even after that I doooo want to get with him but I don’t because I don’t want to continue to get hurt or prolong an already dying relationship.

Is it bad I want to continue things but also want to end things? I feel like I’m making the right decision by not continuing the relationship but I can’t help but like/love him. I love him and spending time with him hmmmm. Maybe I’m scared of settling? I’m unsure.

What do you think? I’d love guidance or advice!