Is it okay to have 1/2 of total calories from protein shakes?

My weight loss is crawling and I need to redouble my efforts to get more protein in.

If I have 2 protein shakes it will be a little over 1/2 of my calorie intake.

I hope this gets me back on track. I will be getting 100g of protein.

You're only about two months out. Stalls are not uncommon at this point.

If you WANT to drink protein shakes and like them, there is no harm in drinking two a day. But you the only special or magical thing about protein shakes is that they are predominantly protein. True, it is hard to achieve those same proportions in a single meal with food but your body doesn't gauge its caloric intake in meals, it does so in whole days. So it's more important to your body that you get mostly protein in a day, which can absolutely be achieved with food. So reallly it's up to you. Will it harm you? No. Will it make you lose faster? Who's to say? Is it worth a shot? That's for you to decide, but know that it is not abnormal to stall where you are and it could simply be a stall, not what you're eating.

What does your surgeon say?  My surgeon says no liquid protein after two weeks......

Good point! Although my surgeon allows protein shakes all along the journey, it's important to follow YOUR surgeon's instructions.

 When I don't feel like cooking/making things or thinking about food (honestly, it's pretty often) I have 2 shakes a day. 
Does your surgeon have you on a calorie per day plan? I just worry about getting my protein in and I don't like eating!

remember that liquid protein is just that...a  LIQUID!  Liquids move out our pouches more quicker than denser protein.  Maybe try this for a couple of days each week and then the other days aim for getting protein in via food and maybe 1 shake a day.