Maybe try this due to the choppiness:
As a younger pony, her parents didn't pay much attention to her which caused her to be more independent. She was inspired by other ponies to try and stay happy (How did this happen?), although it didn't work out as often as she'd hoped it would which causing her to get left out (what did she try in order to make the other ponies think she needed to be left out? Happiness, yes but how'd she go about doing that?). It also didn't help when ponies would make fun of the happiness she had once tried to achieve (why did they make fun?).
Her goal was to stay as happy as possible but usually failed and would end up making her angry and upset (you already mentioned this). She didn't know what to do about her situation until one day, she realized that the opinions of other ponies shouldn't matter and when this happened, she gained her cutie mark! The cloud with the black stripe through it represented that she could cut through the gloomy days with happiness!
Haze Path was walking home when a quiet scream rang softly through the air. Wondering where it had come from, she followed the noise only to see a colt just about ready to hit a filly! Before he could, she got between them and said to the colt "Leave that poor filly alone!" (I'd mention why the colt would be angry enough to hit a filly) which he responded with a snarky: "Well, WHAT are you going to do about it?" "It doesn't matter what i'll do," she stated justly, "just leave her alone!" The colt mumbled, "Fine!" clearly frustrated, and walked away. Haze Path turned to the filly and said, "Head on home, you should be fine now!" The filly said, "Thanks!" and ran towards home. Haze Path smiled and also went home.
Fix this and you should be good!