do you like it? sorry if the romance in the story seems forcely crapped... I base my romantic knowledge on my experiences with my gf through the internet...
Funny, i used to be really into that genre of fanfiction :| And stories exactly like that one :|
But yeah the reason people correct your grammar is that it's really hard and unappealing to read something that looks bad. And yours isn't even the worst i've seen.
All I can say is be careful not to fall into clichés, keep going, don't quit, and keep asking for feedback, you'll get better. This type of pokemon story always falls into cliches. Don't do that.