Help please.. lot is not mine but I built the house

We are married.

Kanya ang lupa, ako ang nagpatayo ng bahay.

In case na magkahiwalay kami, sino ang magkakaron ng right sa bahay?

Well. If you separate, you are still married...
IF get annulment - Did you have big difference in assets before you married? Did you build the house for assets you had BEFORE you married?
It's a law saying something about assets from before marriage belong to each, which can be useful for you in court.

But IF the land had belong to someone ELSE than your wife, then the house would have belonged to LAND owner, IF you don't have a long time LEASE contract. So better hurry try to get a such contract Perhaps your wife would agree to sign it if it include saying you have to pay an interesting for her lease fee sum.
NOTE! Such need to be registrated somehow (I don't know how) so a land buyer would know it, otherwice you can get problem with THEM. Long time lease contracts follow the LAND, so it don't end if the land is sold, BUT you can't have demand at such land buyer if they didn't knew of the lease when they bought the land. But you would still have demands at the person, who signed the lease, but not much use of it, if she has no assets left then...

Or you can try to cover by giving LOAN with the land as security. Perhaps you need to involve a third person, who is on your side. Register such loan too.