How to apply get MP help??

How to appeal to MP for assistance in applying rental flat? I know rental flats are mostly for needy family as it is heavily subsidized. My husband is the sole breadwinner in our family and his salary is not eligible for this. We only have 1 baby as of now & i am the main caregiver for our son. Currently staying with my husband's parents. But we're having conflict with them and its really going from bad to worse. We're waiting for May BTO launch this month. But we cannot tahan stay here anymore and want to try to appeal to MP to get approved for RHS (rental housing scheme). Any idea ? Thank you!