It's probably not what you want to hear, but I think you should just let your feelings about what he did to you drop.
It wasn't at all nice of him, I agree - but he did apologise, and if you love him as much as you say you do, you'll forgive him and forget about it.
I know you've already said to him that you'll forgive him, and that if it happens again you'll end things - but to be honest, in your mind it really doesn't sound like you've forgiven him, otherwise you wouldn't be posting this.
You've been with him nineteen months, you say. Is it really worth throwing everytthing away over this one thing? It wasn't responsible of him, it wasn't kind, it's not boyfriend-like, but he's allowed one slip-up, right?
And as for him getting all upset while you were bowling, saying you were flirting with someone else... let's face it, he was probably hurt you weren't talking to him, had a damaged ego, and was feeling exceedingly guilty.
Isn't that punishment enough for what he did?
I think everything he's saying is just bad feeling lingering from the recent couple of weeks - and I don't blame him for that, because like I said, it really doesn't sound like you've forgiven him.
I suggest you sit down and talk it through with him. Explain that you're not getting bored with him, or anything like that, expressly ask him if he wants your relationship to continue - and if he does, talk things through, arrange compromises to your problems, and explain exactly how you're feeling. Ask him to do the same. And if he still feels you haven't forgiven him, say it again - but only if you truly mean it.
Your relationship will only last through uni if it's what the both of you want. You /both/ need to determine how you feel about it.
Don't talk to us, talk to him.
And don't waste time. If you want to throw away your nineteen months together, and not even give yourselves the chance to see if you'll last through uni, just give up.
But if you want what you otherwise describe as a perfect relationship to continue, run away now and have a word with him. Maybe you'll last through uni and maybe you won't, but you'll never know if don't get to uni - so you have to try and sort yourselves out now.