I’m not sure which meaning of “stoop” you’d like to convey.
The meanings of what you wrote:
Bumaba habang-buhay = Descend all your life – It conjures an image of a bottomless staircase.
Pumatol sa buhay – This could be understood as “condescend to life” but since you used a subject-focus verb, it is not clear as to whether you meant it as advice to others or that it happened to you.
If “to be humble”:
(Laging) Magpak
umbab
â sa buhay = (Always) be humble in life
If “to debase/degrade oneself”:
Magpakab
abà sa buhay = Debase oneself in life
If “to patronize life”:
Pat
ulan ang buhay = Condescend to life – The problem with “patulan” and “pumatol”
though is that, depending on which syllable is stressed, “buhay” might be interpreted as “the living” (which can be considered offensive) instead of the intended “life”. To make sure that it will be understood as “life” I would suggest adding “ating (our)” before “buhay” – Patulan ang ating buhay = Condescend to/Patronize our life/lives