I'm sometimes confused with the use of neither. The basic grammar with it and its counterparts (like either and nor) is clear. My question is which of the following sentences is used in certain situations, or which one is correct (if one of them is not).

1. I neither like it.
2. Neither do I like it.
3. I don't like it either.
4. I don't like it, too.

I would say the 4th one is wrong, but I hear it a lot and wanted to be sure whether I can use it or not. Thanks in advance.