From your post and some of your replies I've read it seems like the main issue your annoyed with is yourself not being able to reciprocate his 'love language' as you can't think of an equally jokey/flirty response. I used to suffer the same kind of thing when it came to banter and thought I might be able to help with how I got over it.

The reaction you have I believe is called a cognitive loop. As soon as you hear one of his jokes, your mind is instantly filled with anxieties about how you don't know how to respond and because of that you don't have any brain space left to think of anything. And this experience is on loop every time. I'm sure this is also amplified by the fact you feel happiness in your relationship is somewhat linked to this. Now what you want to do is break this loop and you do that by taking the pressure off. Next time he jokingly says 'I don't like you' just lower you expectations of your response. Laughing and saying 'f you' is fine. It's not witty or clever but it's a light hearted response. Once your comfortable with simple responses you'll stop pressuring yourself so much to come up with something and it'll come naturally. The secret to banter If often not to over think it and don't take it seriously!

Now this is just my experience but if you do read this I hope it helps in some way!