Really good, I’m quite impressed. I have to look up the proper construction for ‘trying’. Sometimes, but only sometimes, the imperfect ‘was doing’ can be translated with ‘was trying to do’, but it’s not the go-to way to describe that.
In sentence VI. I don’t see why you would want to put a pronoun, and why exactly the relative pronoun in a feminine or, even worse, neuter plural. That makes negative sense. Just say equus defatigavit et consistit. If you want to know personal and demonstrative pronouns of the third person (he, she, it, they them, this, that, these, those and so on), I’ll maybe put something here tomorrow.
In VII., the nominative makes no sense unless the horse is speaking about itself. “I, the horse, fed hay!” But to whom? That’s were a grammatical case for the receiver of a benefit would come in handy, wouldn’t it?
On a side note, up to Cicero’s time, the spelling for words ending with -uus, -uum and so on (even if the u is a v, as in naevus) were spelled -uos, -uom and so on. So Cicero would be accustomed to see equos in the nominative singular.