marks the subject of the sentence. That means the one doing something.
marks the object of the sentence. That means the one being acted upon.
When you want to say something like "He helped me". "He" is the one doing something. So, "he" is the subject. "me" is the one being helped (the recipient of the action), and so is the object.
If you write
>
you're saying "He helped me."
If you write
>
you're saying "I helped him".
Or, perhaps consider the following:
>
which means "I saw the dog". Whereas
>
means "The dog saw me".
So, it's not so wrong to say , but if you're the recipient of the action then is not likely to be correct unless the verb is passive:
>
"I was helped"
I hope this ***helps**. (Excuse the pun.)