I felt really good because I ran along the coast, and I relieved my many stresses.

I agree with the other commenter that it doesn't sound right to say "I relieved my many stresses"-- this is because English doesn't talk about stress relief in a reflexive manner. The thing that relieves stress is never oneself.

I would say that "the run relieved my stress" or "I felt less stressed (because of the run."

I rawent for a run this morning.

This is more idiomatic, though the original is also fine.

I felt really good because I ran along the coast and I relieved my many stresses, which had been at a high level.

We don't really say "stresses" unless we're discussing "stress" in a language or music sense.

With the new phrasing, "reduced" might be better than "relieved."

So, I reduced my stress is better?

I studied that after for is with - ing but in this case is not. Why?

"I relieved by stress" is best, but it suggests that your stress more or less went away (at least temporarily), whereas "reduced" or "lowered" ("lowered" seems more common, actually) suggests that you may still be under a bit of pressure, just not as much anymore. So it depends on what you want to convey.

Sorry, but I'm not quite sure which part you're referring to, or how it connects to this specific sentence? Quotation marks might also be helpful here.

I'm sorry. I'll write more clearly now. If I use "for", Should I change a verb to -ing? Ex. I woke up early for "making" breakfast.

Thanks, that makes more sense. Off the top of my head, it’s true that we need the “-ing” form after “for,” but in your example, “to” would be better. I associate “for” with adjectival phrases, like “an app for tuning one’s instrument.”