If you grew up in the era of grammar education that I did, you were like told something along the lines of: "Add a comma wherever you would take a breath in a sentence."
If you looked little further, though, you realized that wasn't actually true.
Commas are our friend. They prevent run-on sentences, help create organized lists within sentences, and so much more. But they can be overused.
Commas often get defended by writers or readers who prefer things a little more informal (or take a lot of breaths in one sentence.) You also have the philosophers who would argue the severity of using commas at all.
A "splice" is when you use a comma to connect two independent clauses. This is grammatically incorrect because you need either a conjunctive adverb or another connecting term in place.
So why in the hell does this error come up so often in writing? Is it because of the take-a-breath rule? Are we not recognizing clauses?
Personally, I think it's because we've seen great authors break this rule time and time again- and writers of Classic Literature no less. If they can break it and be successful, why can't I?
You can't break the rule because you're not breaking it like Hemingway or Melville is. Have you ever heard someone tell you that you need to learn the rules before you can break them? The same concept applies here. You have to walk before you can run.
For now, slow down. If you think you're using too many commas, you probably are. Substitute it for a period or even a semi-colon