Stuck! Please help!

My boyfriend and I have been in a bad place lately, we just keep arguing and aren’t listening to each other. We came to an understanding on Sunday to actively work on getting better because we want to spend the rest of our lives together. We see each other everyday but I feel he’s been a bit distant. He said he needs fine because he’s scared if we go back to normal we will go back to our old fighting ways because we already have what we want. I believe him to an extent but him not being the same with me is killing me. If you’re going to tell me to break up with him kindly keep your comments to yourself. I’m just here looking for support and help and similar stories to help me get through this. Relationships aren’t always rainbows and butterflies, but in scared he’s gonna wake up one day and say he doesn’t want to be with me anymore. And even though he’s said he’s here and he’s willing, I’m just scared he’s stalling.