Is it quicker to backup my phone from my computer? This is taking way to long

The amount of time it takes to back up your phone depends upon the size of data you are transferring.

Also, is this the first iCloud backup you are doing on the device? The first backup will always be long. After that, they are much shorter. Even an iTunes backup, the first one will take longer, especially if you encrypt it to ensure all of your data is saved like Health, and passwords, etc.