Am I getting better?

I'm starting to wonder if I'm really getting better.
Over the last year I've had my medications upped so many times.
Every time I go to a higher dose I feel fantastic for a while, I'm so stable, no ups, no downs. And then I have a dip, or a high, and everything just goes out of control.
I've recently been very manic and then crashed very low. The mania was caused by steroids for a serious chest infection (so bad I was in hospital on oxygen, they HAD to give me the steroids to clear it even though they knew they made me manic). The crash lasted a week or so and I was suicidal. I'm mostly back to normal now, but I don't feel stable.
I was perfectly stable before this, absolutely perfect.
But now I feel slightly off.
I had my medication put up to 2000mg a day, of Epilim Chrono in July. I've been so good since then. Only one manic period and that was whilst I was on extra dosage of my steroid inhaler for my asthma.
But now I just don't feel that perfect stability.
What's going on?
I don't feel massively depressed, or massively manic, just a bit meh, and a bit grry.
But that's enough to not feel quite right.
And I hate it.
I'm still on antidepressants til the end of the week to get past the crash.
But I'm a bit scared that every time I have a BAD phase I get worse, much worse, and my medication needs upping. They can't up the Epilim much more, my liver will start to fail. I already have to have 6 monthly blood tests to make sure it's ok. And the maximum dosage is something like 2500mg a day.
This is really starting to worry me.
I like Epilim. I don't have many side effects other than serious weight gain, and I've heard horrible things about other mood stabiliser side effects.
I really don't want to change medication because of that, and because of the tailing off and tapering up to another drug would mean I wasn't medicated properly for a while and I just can't do that.
I'm really confused.