On a long journey, need your help.

Hey there, I've recently found out about this amazing website and i would like to introduce my self.

name: Saeed
age: 19
country: dubai

i'm 6'6, 155 kilos ( was 165) and my goal this year is hopefully reach 100 and have a muscular body.
i bike 4-5 times a week ( intense/moderate and switch it every few minutes ) i also walk after every meal.
im at the gym pretty much every day im not sore

my biggest concern right now is my calorie intake, a few websites said im at 3-3.2k but i barely pass the 1.5k intake, some days i'd feel fulled and probably stay below 1k, would consuming below your bmr by 1k+ reduce your weight loss? im new to all this neutrition information, thank you in advance.