It's really beautiful when the wind whips bigthe waves all over again.

The grammar is not wrong but "whips" is not a very common way to describe actions of the wind or sea...

By the way, I crossed the one month mark here, it's great.

Anyway, I spent some time onat the beach this evening.

On the beach is sounds literal as in what you're are trying to specifically convey is that you were literally on the sand at the beach. It's more natural to say 'at the beach' to convey that you were there for some period of time

I a'm glad that I had the opportunity to see one of the greatest wonders of the world again.

The fact that you used 'Anyway, ...' in the earlier phrase makes this text sound conversational as in you want the reader to read this as if they were hearing someone saying this to them. In day to day talk natives say 'I'm' unless they are annoyed or something in which case they might be more specific. To make everything have the same casualness to it, it would flow better to write 'I'm ...' because you used 'Anyway ...' in the phrase above

It's really beautiful when the wind whipskicks up big waves allover and over again.

- I've never heard the verb to whip used when referring to waves, probably fine but kicks up is something that would work.
- all over again sounds weird here because you haven't talked prior to this sentence about big waves being made by the wind. Writing over and over again is a bit poetic but I think conveys what you are trying to say

By the way, I cropassed the one month mark here, it's been great.

- I think what you are trying to say is you've now spent more than one month at the beach, the natural way of saying this is to say I've passed the one hour/four year/3 month/2 day mark. Using crossed is okay as well but it's a bit more natural to use passed
- You need to add 'been' because you are referring to the past month that you have been at the beach and that's it has been great. This occurred in the past so need to put 'it's great' into the past -> it's been great

It's a habitThe beach is my drug now.

This is a little unclear, I'm not sure what habit you are referring to here mainly because in English at least, living somewhere is not generally considered a habit (but I think you mean your really liking the beach that it's now a part of your life). If you want to really emphasize how much you like it you could write something like what I have put as an example, this is also a pretty casual phrase as in it's something you would hear someone say so it fits the vibe