Hi and welcome to COL
If you only got your pup on Saturday and she's only 8 weeks old then in all honesty you're expecting a bit too much of her at this stage. She is still a tiny baby and will take a while to adjust to her new home and situation. When you leave the house dogs don't think 'oh well that's the owner off out, time for a sleep before they get back'. They live in the here and now and all they know is that you're gone - they don't know if you're coming back and they have to be taught that it's ok to be left and that you will return. To such a small puppy an hour is a very long time.
You teach them this by building up the time you leave them very gradually. Literally starting with leaving them in a room or their crate and shutting the door for 30 seconds and building it up from there. The key is to go back to them before they react and begin to get distressed but if this isn't possible then wait at the door and only go back to them when they are quiet, even if it means flinging the door open in the second it takes them to draw breath. At 8 weeks she also won't be able to hold her bladder and/or bowels for long yet, at that age they need to go out roughly every 20-30 minutes or so.
Another puppy will NOT help, in fact you would 99% for certain end up with not one but two very distressed, crying and messing puppies who are feeding off each other's anxiety. She wants human company and reassurance, not another dog. Certainly for older dogs having a companion is great but it is still not a substitute for proper human interaction and isn't an excuse to go out and leave them alone all day (not saying that you're doing that, it's just a general point).
It's really great that you've taken time off work to settle your pup in, that's a really good idea and you should definitely have this sorted out by the time you go back although bear in mind that even then the absolute maximum that any dog should be left is 4 hours and for a small puppy it's really less than that so if you're out at work do you have someone to come and sit with her or is she going to daycare?
Hang in there, with patience and a good routine in place she will be fine. What is her name?