Depressing thoughts are boring. Let's stop having them.
Land surface area of the earth: 148,940,000 square kilometers.
World population (min. estimate): 6.6 billion
(1.4894 × (10^14)) / 6.6 billion = 22,567 square meters per person, or close to 250,000 square feet. Thus, even if we were all evenly spaced out among to every corner of the earth we'd each have a plot about the size of a big Wal-Mart. If we were all equally isolated, we'd still be within walking distance to dozens of other people.
Of course, we don't live like that. In fact, even if everybody that lives in Greenland spread out as much as they could they'd be closer together than that. Even the most isolated person here isn't more than a couple hundred feet from another human, one they could potentially relate to. Even a total stranger is more like you than unlike you, simply by being human.
So, as cheeky as this may be, it's pretty clear that you really aren't alone. You only feel alone because you don't know how to connect with certain people on certain levels. Like anything else you don't know how to do, though, you can learn. It is not a fact of life, it's a feeling.