Oh yes...lactose can certainly have that effect. Which makes it inconvenient as heck b/c most pre-made shakes are heavy in lactose. Generally now I use protein powder (I like IsoPure, BioTrust and Purely Protein), and make my own shakes with either lactose free milk, oat milk or almond milk. Eggs don't bother me, (but I do know they bother some who are lactose intolerant). so I eat them a lot (egg beaters, because of the calories). When I did puree's, I actually ran chicken through the food processor with a little broth and it made a thick, high protein soup. It sounds gross but with a few spices it wasn't that bad I also had to give up cottage cheese and yogurt, although I did try almond milk based yogurt, but didn't care for it. Some people do like it though, so maybe it's worth a try for you. Peanut butter and almond butter are also a nice treat but the calories/fat can be a problem if you have too much, of course.
Hope that helps a little. It's a challenge, for sure, but you got this! I've found that this whole process is full of ups and downs (and not just the weight either) but when I focus on the big picture and remember why I did this, it makes it all worthwhile!