If i can help you more

forlanIs below sentence right? No.

I am sorry I cannot help you much. If I can help you more, I will be pleasant to help you.

Is it possible to join those two sentences? No. The meaning is not really clear.
There must be some reason why you can't help

forlanIs it possible to join those two sentences?

There is probably a way to do it, but that would be too much for one sentence. And I don't see the two as really logically connected. I recommend saying one of these, not necessarily combining them, however:

I'm sorry I can't help you any more than that.
I'm sorry I haven't been able to help yo

Thanks Avangi,

The situation is like this:

My friend asked about a bird. Unfortunately I cannot explain the bird very clear. I am pleasent to help him but I have no much knowledge about the bird.

I wish I could help you, but it's not something I know much about.
I would like to help you, but I'm not able to.