Play more ragtime, swing, blues, jazz, pop, rock. Counting is at best an initial aid to getting started, an approximate guide for isolated situations. Rhythm at its finest is a deeply felt sensation which transcends notation. Also listen to other music with rhythm, not trying to count it but just feeling it. Imagine rhythms in your mind while you go about your daily business. I had always done this and it came as a surprise to find other people did not do it.
Improvise rhythms on any convenient subset of notes simple enough that you don't need to worry about what you are playing. And don't worry about the notation of the rhythms you invent; sometimes notation would be approximate or may not exist at all. In other words, don't play rhythms to fit an imagined notation. Then over time, you will be able to sense at once the rhythm a composer tried to capture in his notation, and will not require counting or other aids.
In fact, I think the improvisation of rhythms - constantly varying ones, don't grind the same ones day in and day out obviously, else you'll learn nothing - would be just about the most effective thing to do of all.
It will take time though, months and years rather than days and weeks.
Topic: Advice on improving Rhythm