How do you do THAT?

Blood pressure increases.

Yeah, that's true. It's not a myth. Even Wikipedia confirms it, so people with hypertension should avoid excessive consumption.
But caffeine also has pleasant effects. For example, it suppresses the feeling of hunger, which is what "Herbalife" and other "miracle pills without diets" take advantage of. And, of course, coffee is invigorating.

It's funny, at first I drank no more than one or two cups a day, but in the last few weeks, I've been drinking at least three or four.

Addiction is normal. Over time, the effect decreases, and you have to increase the dose. This happens to me not only with coffee but also with chocolate, TV series, and even work. That's why I take 2-week breaks from coffee, chocolate, and TV series. Breaks from games and work happen on their own. And since I'm already looking things up on Wikipedia, I'll share another quote:

In small doses, it has a stimulating effect on the nervous system. With prolonged use, it can cause mild dependence – theism (a disease). In large doses, it causes exhaustion, and in doses of 150-200 mg per kilogram of body weight (80-100 cups of coffee in a limited time), it causes death.

So, watch your dosage, Revan.