I stopped listening the all japanese music for a few months waaaay back and started listening to, god forbid, rap music
. X Japan pulled me back in and i haven't left J music since. That said, before i discovered Jpop i had never actually been a fan of any music. I couldn't name one artist or group i liked, always just saying someone my brother or sister listened to. Through listening to Jpop and Asian music on the whole, i've found that I've opened up a lot more to western music, though what i like in minimal and not very mainstream (except for Shakira). I think it's possible to enjoy and accept all music if you like it. There's no reason to put a firm barrier down and say "I'll ONLY listen to Jpop".
I must admit though, there's not a huge lot of really decent artists coming out in the last year or two. Apart from enjoying the likes of Aya Hirano, personally I don't think Jpop has had a really decent new artist since YUI came along, whereas before her, we had the likes of Otsuka, Ayumi, Utada, Kumi etc... Nobody these days really seems to make an impact. Aside from discovering my ridiculous love for H!P in the last 2 years, i spend a lot of my times discovering OLDER singers. Like 80's artists and bands such as Rebecca, Mari Hamada and more. It's really nice to see how Jpop/rock has progressed over the years.
Anyway, don't force yourself to listen to jpop if you don't fancy it. Leave it a while and who knows, you may catch on to a new artist and start listening again in future.