First, I am not a lawyer, this is not legal advice, if you follow my advice and get sued then it's your fault not mine.
That said, you've talked about "copyright issues". I'm going to break this down into two questions:
1) If I get sued for copyright infringement, will I win?
Probably! Game mechanics can't be copyrighted, so you're safe there. If "potion" isn't officially in the public domain then it's only one court case away from being so. "Ember" should be reasonably easy to defend - I know that ability name is used elsewhere. The "ball" is probably the sketchiest thing you've got, and if you just change the ball you're probably gold.
2) Will I get sued?
Unless you have a nice big legal war chest to rely on, getting sued is almost as bad as losing. You can't hope to match Nintendo's legal funds. It will not happen. You'll go to court, and you'll probably blow thousands of dollars just on prep work. And then even, if you win, there's no way you're getting that money back without a second court case - more money, and you're not even guaranteed to win that one.
So, as I see it, you have two realistic approaches ahead of you.
First, you can change things up enough so it's not as sketchy. Give your game a feeling of its own, not one copied from Pokemon. Don't use "gym trainer" and "tall grass", invent stuff. Instead of four abilities, use six. Give your PC a seven-monster party, and do something new with the monsters. Throw out two thirds of the Pokemon elements and make your own. (You're probably safe with "fire", but if you have "psychic", "bug", "rock", and "ghost", people will look at you a bit odd.) "Inspired by Pokemon" is safe. "Exact copy of Pokemon" isn't safe.
Alternatively: get legal counsel, get legal insurance, and form an official company to get at least a slight hint of the corporate veil going on. It'll cost you money, but it'll be a lot cheaper than being sued into oblivion by Nintendo, who will probably cheerfully drop the suit the instant you sign over all your intellectual property to them, and not a moment before.
Again, not a lawyer, not legal advice, get a lawyer.