I know exactly what you're saying, but that's not what I'm saying. I'm just giving you a suggestion on how to increase your metabolism, which will in turn increase your appetite. If you're not hungry, either your eating massive amounts of food or metabolism is lowered. I had recently worked my way up to 4k and finally hit that point where I wasn't hungry between meals, so I backed off. At 3800 I am hungry by the time I get to my next meal. The last one of the day is difficult to finish for me.
What it takes to get your stomach to expand is routinely stuffing it day in and day out, it adapts over time. By 2 weeks you should be getting used to the increase in food volume.
Another important factor is digestion. Considering what you're eating currently I'm assuming your body probably doesn't like it and it's making you bloated and feel full all the time. Everyone is different, for instance I can only eat beef once a day and be able to digest it decently, and even then I have to substitute chicken sometimes because it starts bloating me and making me feel crappy. Some guys can slam beef 3 meals a day no problem. For me (and most) good old chicken and rice (breast or thigh) digests the most efficiently, which means I'm able to utilize it instead of just being the miserable middle man between the plate and the shitter lol. I would cut back veggie volume so you don't feel so full, but add in some psyllium husk fiber 1-2x daily to aid in digestion. I also take probiotics every so often to help. Enzymes with my beef meal help it breakdown better. Years ago, I had to add in betaine HCl with 2-3 meals per day so my stomach could keep up with the food intake, which was around 4600 calories at that time. Not advisable if you have gerd/reflux issues though.
Main points:
Ditch shakes. They're crap and probably causing more harm than good
Find which foods work best with your body. Rice is usually be easiest carb to digest
Force feed until your stomach expands. It will
Lower food volume when possible
Use healthy fats and carbs to make caloric increases
Tune up your digestion