Help!!!! I'm trying to bulk but

Excellent question!

Things like this unexplained loss are kinda weird, but you might have lifted your way to a natural break point in your body's economy. It's not a machine so things like this are actually confirming this variability. This is exactly natural and predictable - not easy or predictable.

Your hormones (testosterone actually) just hit the wall and having a little oopsy is what's going on.
The responder sbove is dead on the money! You need to eat, but you need to eat certain stuff to crank up your taxed Endocrine system!
Now is the time to hit the following
1. Cinnamon - bad *kitten* blood sugar modulation par excellence
2. Flaxseed - secret plant Alkaloids
3. Oats - fed to champion race horses to win big money
4. Ginger - no better for active recovery with massive hit of potassium, phosphorous, manganese AND 9% protein
5. Coconut Oil
6. Cottage Cheese
7. Red meat
8. Leafy greens
9. Bananas
10. Chillies

Google them if you are doubting why these particular items are needed. Authority Nutrition is a brilliant straight forward source of info. Basically, blood sugar is ceased to be delivered to the muscles to create ATP (ATP is the fuel source for all cells Ref). This is the evil result of insulin insensitivity... the sugar is not fueling the cells as before, so strength declines as does fibre recruitment - good bye muscle mass! Hello metabolic syndrome!
Get plenty of sleep and stress less, drink lots of water and reduce session time - when your bathroom scales read bigger numbers you'll know it's business as usual! Ups and downs are like the reasons, cycles are a natural phenomena in nature. We are not machines, actually, machines can have a safe working load, when exceeded results in a sudden loss of function!