Correction: "I tried to mollify myself by eating chocolate after a stupid situation happened to me yesterday." "Mollify" is one of those "big words" people would avoid in casual conversation. It would be common to see written (although not in casual places such as forums or chatting), though, and would be used by those who are comfortable with exercising the breadth of the English vocabulary. Using it would depend on your audience. I repeat: Using "mollify" and your above sentence DEPENDS ON YOUR AUDIENCE if you were to ask if it sounds "natural." If I were to speak to someone to whom I feel is my intellectual equal or superior, I would not care if I dropped it. If I were speaking casually with intimate friends or with those whom I perceive to not have as great a grasp of English (you would be surprised to know how many native English speaking college students don't speak nor write English well), I would more likely refrain. Neither of the above situations would rule out using it. Even if I did use your above sentence in the latter situation, people would still understand me, but I would be laying the foundations of being a snob. Using "stupid" implies a sense of casualness in the conversation, so pairing it with "mollify" is odd.

Native speakers of English would say the above, especially when conversing. Rachel is correct on the grammatical point, yet it is common among native English speakers to tack on -ing to express a continuous/active state. If you are speaking this to someone, I would say go ahead. It adds a relaxed flair to your English such that your English won't be stilted as most ESLers are. But I don't suggest writing it unless it is dialogue in a story. For any future questions, just remember not to mix up conversational English with written English. They are different in the sense that grammar rules are really relaxed.

I strongly suggest that you look up all those nouns in the dictionary before you choose one of them. They depend on the context of your sentence. Each of them are correct, but that doesn't mean they would be the "best" considering different context and situations.

"Could" implies a hypothetical situation. In here, you are stating a fact, which is why Gabriel is correct in offering the choices of tense correction. In his initial change, he changes the first verb tense "is" to "was". This implies that even in the past he would not have been able to do it. If you do use "is", then you must change "could" to "can" because you are speaking about the present.

You could just say what you said, "I am touched by (whatever the person did or how they made you feel)".

Everything after "The education" in both cases are correct. I'm not sure what you mean by "The education." That is the problem with both sentences. A more typical phrase would be "School..." If you said, "Their education..." that has a whole different meaning.