iPhone 6 (iOS 9.1) backup to iTunes (12.3.2.35) is painfully and unbearably slow then typically doesn't finish.

I have only ever backed my phone up (iPhone 6) directly to my laptop (while plugged in via USB w/iTunes) and have never ever backed up the device anywhere else or backed up over wifi.

I have not been able to successfully back my phone up to my computer for almost a month now as I've encountered an issue I haven't seen before. The backup itself goes PAINFULLY slow on step 2 of 4 during the syncing process. So slow as in, its taking 2 or more hours to back up and eventually doesn't complete the backup itself. It usually ends with an error of "iTunes cannot complete the backup" or "backup is corrupt." Backups for me usually take about on average 5 or so minutes (no more than 10 minutes on the longest ever backup), so this step of the process taking more than 2 hours is frustrating me beyond belief.

I ended up finding this thread: itunes will not backup my iphone 6 which discuses a similar issue, but the strange thing with my issue is that if I skip the backup step 2 of 4, it will continue on and finish out the sync WITHOUT creating a backup. I reset the Lockdown folder (as per this thread: If you can't make an iTunes backup of your iPhone, iPad, or iPod touch - Apple Support) and backups are still taking 1+ hours (and then not completing). I also located the backup file and renamed the folder "old" as to let iTunes start a new backup folder and I am encountering the same issue of the backup itself taking FOREVER. I tried several other Lightning cables I had as that was another suggestion from another thread and the same thing – unbearably slow backup speeds (that end in failure). As per another comment, resetting network settings on the device sometimes does the trick and I did that as well with no luck.

I know I'm not running the most up to date iOS on my phone, but since I haven't been able to back anything up I'm kind of in limbo. Should I update my iPhone to the new iOS and maybe that will fix my backup speed issue? It's going to sound dumb but since my backup isn't up to date, I'm worried that if something goes wrong I'm kind of screwed.

Anybody else have any similar issue like this, or other suggestions on ways to troubleshoot?