Protein Shake Questions from a Newbie

Hi everyone! I just had my surgery date scheduled for April 29th last week. It's been a loooong 6 months or so of doctors appointments, approvals, testing and procedures. I can't believe it's really happening!

So, when I had my meeting with the nutritionist at the surgeon's office, she went some of the protein shakes with me, but there was so much to cover in so little time I didn't get 100% clarity. I've been doing a lot of research here and Googling but I'm having a hard time making heads or tails of what a "protein shake" means post WLS. 

In addition, I am severely lactose intolerant so I know that a lot of pre-made shakes and shake powders have whey protein in them, which wouldn't work. ALSO (and I hate to be picky) Splenda gives me horrible gastro side effects (no need to go into details here!) so if the shakes or powders are sweetened, it would have to be with aspartame. 

Can anyone help me out? What kind of powders or shakes can I eat? I love unsweetened almond milk so my plan was to use that in place of milk if needed.

I think for the 2-week pre-op diet I need to be drinking like 4 protein shakes a day so any help would be very very very much appreciated!

Thanking you all in advance!

P.S. How to I edit my signature/ticker?