Some of the weight loss could be water weight. People your size could only lose 4lbs Fat a week max anyway, so you're losing roughly 6lbs, which isnt vastly over doing it.
I think you might be overtraining, so cut Wednesday out. 6 days is a bit much, for someone like you.
You also aren't getting much work for Legs in really, with weights, I'd add that in.
Also Tuna is high Mercury, limit to 2-3 cans a week.
Meal timings are good, obviously reliance on shakes is something that needs addressing, most are Micronutrient defective, so you're potentially getting low amounts of Micronutrients per day.
One a day should be adequate after training, and maybe half at Breakfast.
For quick easy food types, have stuff like Whole-grain Cereal, possibly powdered Flax, Low Fat Cheese or Peanuts as snacks, as the last three are good for Carbs, Proteins and healthy Fats as well as other things. Whole-grain is Beta-glucan, so good for lowering Cholesterol, same as healthy Fats.
Incoroporating veggies in there is also an option. Right now Fruit is not a biggie, except ones like Tomatos, Peppers and Cucumber, the ones not classed as sugary or acid aren't important.
If you can find a way to scale down the 6lbs a week to around 3-4lbs, you'll avoid excess skin issues further on down the line, but for a guy in your position, to have gotten this far in 5 weeks, in what seems like their own steam, deserves big, big props and you can be very proud of yourself.
The main thing is patience, tolerance and understanding of yourself. If you make mistakes, pick yourself up as soon as possible, and keep doing your best. I'm sure on this evidence you can, and I wish you all the best trying