Contacts Syncing and Retrieval

Hello!

I just got a new macbook air and tried yesterday to transfer all the data from my old macbook air to my new one. Everything went smoothly until I discovered that my photos and messages wouldn't update beyond a certain point. I went to the settings on my iphone and realized I needed to sync my icloud because it had been a while, so I did that and to it let me transfer my photos and imessages. I tried everything out, texted my dad from my laptop, everything was good. Then I realized that not all my contacts had synced. All phone numbers I had recieved from this summer or any contacts names/photos I had changed recently weren't saved. I googled how to remedy this and it told me to:

1. On your iPhone, go to Settings > [your name] > iCloud.
2. Turn on Contacts.
3. Tap Merge.
4. Then, on your Mac, click on the Apple menu in the top left-hand corner.
5. Click System Settings > Your Icon > iCloud > Show More Apps.
6. Switch on the toggle next to Contacts.

I did this, and instead of adding contact names, it deleted all the contact names I did have access to, and on my iphone, it reverted all my contacts to old data and lost all the cpnatcts I had created in the past few months. My question is how do I revert my iphone contacts back to the most recent data? And then, how do I sync that data to my macbook? Thanks!