Computer can't handle iPhone backup

Hello,

On 9/2/20, my computer tried to backup my phone like normal and it got stuck and wouldn't let me do anything except for go to factory settings and lose everything. I still have all the backups but my computer doesn't have enough memory (I think that's the issue), so I haven't backed my phone up since then. I would like to access backups that have the majority of my pics on them.

What would you suggest? Can I delete old, old, old backups from like 4+ years ago? Can I move it to an external drive? I find it hard to believe that Apple somehow only wants you to access the backups from one spot and one spot only.

Thanks in advance!

Dawn