Photos stuck on "downloading x items"

Hello everyone,

Today I noticed that my Photos album was stuck on "downloading 1 item". I wouldn't go away and I could not find the photo/video which it was downloading. On the other hand, my iPhone's Photo library was working fine.

I could take new photos and they were uploaded to the cloud, and my Mac downloaded then correctly, but still on Mac it said "downloading 1 item".

FIrst things first:

- Macbook Air 13", early 2015, Mac os Sierra 10.12.6

-iPhone 6s Plus, ios 11.2.6 and I will upgrade to 11.3 as soon as possible...

I tried to troubleshoot this problem.

1.Turned off iCloud photo library

2.Deleted the existing photo library from my Mac

3.Created a new photo library (default) and set it as the system library.

4.Turned on iCloud photo library and photos and videos started to appear on my Mac's photo album.

+ ALSO tried to make a smart album (or what it's called) and selected the "unable to download to iCloud" --> 0 items there. But I think the problem is that my Mac's photo library is downloading something and does not have any progress going on...

Now, it is stuck on "downloading 7 items" !! I have no clue what items those are. Two video files will not download (error, try again later) but I'm sharing my iPhones network to my Mac so it might be the reason (the size of those videos is over 100Mb for both so maybe it need wifi connection to download them completely, I dunno....).

I'm just wondering what in the name of Earth is going on! Everything was working fine like few days ago, and suddenly BOOM. I have not taken a lot of photos since that.

Also, in iCloud.com the photo library is correct and working.

What can I do to make this work again! I am so mad at this problem now...

I am super worried about if there's like corruption etc. because what will I do about it? If there's corruption going on, what are my options? This is just overwhelming for me....