Struggling with Persistent Acne: Seeking Answers and Solutions - Dermatology

I don't know how to improve acne and can't identify the cause. (Long text)

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Hello, doctor.
I have been experiencing acne since the first year of junior high school, and it continues to persist even now that I am in my first year of college.
I cannot identify the cause, so I would like to explain my situation and seek your advice.
From the first to the third year of junior high, my acne primarily appeared on my forehead, with very few breakouts on my cheeks and nose.
I experienced both closed comedones and common acne, with breakouts occurring in waves; it seemed like every inch of my forehead had been affected.
I even had painful large pimples that resembled mosquito bites, which were swollen but did not have a visible head, and when squeezed, only clear fluid would come out.
At that time, I suspected that my bangs might have worsened the acne.

My daily routine and diet were normal, as I ate my mother's light and healthy home-cooked meals.
However, my menstrual cycle was irregular, occurring only three to four times a year without a consistent pattern.
I consulted a gynecologist who said this was normal and that I just needed to wait for it to regulate itself.

From high school to college, my acne shifted to primarily appearing on my cheeks, with the same pattern of breakouts: one batch would clear up, and then a few days later, another batch would emerge, creating a landscape of acne.
Although I still had bangs during this time, I experienced very few breakouts on my forehead, with only occasional closed comedones.
My routine and diet remained normal, but due to a lack of exercise and academic stress, I gained ten kilograms over three years, with my BMI increasing from 18.0 to 20.7 (I have heard that weight gain can lead to more acne, but I am unsure if this is correct).
My menstrual irregularity persisted, and I began treatment in my senior year of high school, taking Diane for a few months, but it did not improve my acne.
The doctor later diagnosed me with a natural deficiency in progesterone, stating that I did not have a disease, so I take medication or receive injections every three months to help regulate my menstrual flow and prevent tumors.
After visiting the gynecologist, I also consulted a dermatologist and was prescribed topical retinoids.
There was noticeable improvement in the first couple of weeks, but then it returned to the previous state, so I stopped using it.
This past year, I followed the dermatologist's advice to use a milder cleanser, Sebamed, and recently tried using an enzyme soap to wash my face.
Neither has significantly improved my acne, although the enzyme soap seemed to work slightly better.

For the past month, my washing routine has focused on the T-zone, while I only let the foam from the cleanser briefly touch my cheeks when rinsing with warm water.
Sometimes I massage my cheeks a bit before washing.
Occasionally, I might wash for too long or scrub my face, leading to some areas becoming slightly flaky.
In such cases, I apply a thin layer of aloe vera gel, which is commonly available at drugstores, and if I pay attention the next day, the flakiness usually does not occur.
I wonder if this washing method is problematic?
Unless I have a performance in a club, I usually do not wear makeup, aside from occasionally applying aloe vera and sunscreen; I do not use any other products on my face.
My mother is quite surprised by my acne, as she believes my skin type is very similar to hers and that I should not be struggling with acne.
She has observed that I often touch my face or pop pimples, but I have significantly improved in this regard over the past couple of years and rarely touch my face, yet the acne persists.
Currently, I have many shallow acne scars on my cheeks.
My skin's oil production is manageable, and I do not need oil blotting papers.
I believe that aside from the acne, my skin is generally in good condition.

I am truly at a loss as to what could be causing my persistent acne, and it is quite distressing.
I would greatly appreciate your insights.
Thank you for taking the time to read this lengthy message.
Thank you.

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Qiqi, 10~19 year old female. Ask Date: 2016/02/19