我不会说汉语很好It may have two confusing meanings，which can not make out from reading pauses and emotional elements though I have tried. 我不会说汉语很好=I can't speak Chinese well or =I don't think highly of Chinese. Maybe it depends on the situation .Anyway，I don't think it is standard Chinese. 我不说汉语很好，this sentence tend to be the latter meaning which means I don‘t think highly of Chinese.Because from“不说”，we can see it's emotional coloring is negative and holds a denial attitude to the object ”Chinese”.

我不会说汉语很好 means “I can't speak chinese well” 我不说汉语很好 means"I don't speak chinese well" 会 means "can",means have the ability of doing something:) but"我说不好汉语"or"我的汉语说的不好" is more standard:)

我不会说汉语很好 ----8words 我不说汉语很好---7words . 意思差不多。

I think the two sentence are wrong, therefore no need know the diffirence between them. 我的汉语说得不是很好 anyway, chinese poeple can understand u rightly, Just go on study