I drink four shots of coffee every day (I make myself a double shot in the morning, then have another double shot in the afternoon), and I still come home exhausted and worn out. Today, for example, I went straight to bed and slept for two hours. Even adding a can of white Monster during the day doesn't help—I'm still tired no matter what. I feel like my pee is all stimulants and not a single drop of water.
Try pushing that afternoon cup back or cutting it out first.
When you say you feel tired and exhausted, what exactly does that feel like? Is it the kind of sleepiness from not getting enough sleep, or is it more like having no energy at all and trouble focusing? Also, without knowing what time you go to bed, how many hours you sleep, and whether there are other medications or health conditions involved, it's hard to tell whether this is tolerance or something else.
The real issue may not be stimulant tolerance, but rather that long-term high-dose caffeine has disrupted your sleep architecture—you rely on coffee to get through the day, then sleep poorly at night, creating a vicious cycle where the more you drink, the more exhausted you feel. That said, this is only speculation. Confirming it would require looking at your daily routine and when you consume caffeine; drawing conclusions from a single description is premature.
First, record your food intake and the times you feel sleepy for three days.
If you're thinking about cutting back, don't go from four shots straight to zero—that can easily cause headaches and fatigue. Try dropping the afternoon cup first and see how you feel for a week or two. But this only applies if you don't have other health issues going on. If the tiredness keeps getting worse or comes with heart palpitations, see a doctor first rather than trying to adjust your coffee yourself.
Four shots plus a can of Monster adds up to a pretty substantial amount of caffeine. If you keep that up every day, the monthly cost of coffee beans or convenience store coffee isn't small either. More importantly, all that money buys you is feeling sleepy during the day and crashing the moment you hit the pillow at night—a pretty poor return on investment. It's worth recalculating whether this is really worth it.