Taking progesterone without estrogen in early peri (39)

I started on HRT a few weeks ago after experiencing perimenopause symptoms for over a year (started around 37/38). I'm doing all the things to improve my health: eating well, on a low dose GLP1, strength training. I've had a constellation of symptoms that all scream perimenopause: 3am wake ups, anger and irritability in 2nd half of cycle, shorter more erratic cycles, face acne in new places, itchy ears. Last year, my gyn told me I was too young for HRT and gave me progestin only BC, which made me bleed horribly and I went off within a month.

I finally got up the nerve to book an appointment through Midi after hearing it advertised on every podcast in my feed. Vaginal estrogen at night has gotten rid of the terrible itchiness and made sx pleasurable again. Nightly progesterone has reduced the frequency of early morning wake ups, fewer nighttime hot flashes, is improving my cycle frequency (went from 24 days the past several months to 26 this month), and helping with my mood during the luteal phase. It's amazing, I spent years on SSRIs and anxiety meds and felt like I was living life underwater, but a few weeks on progesterone has had a larger impact on my mood than any of those meds.

My question is around taking the progesterone daily without an estrogen patch. I was prescribed 0.0375 patch, and it gave me such horrible breast pain and brain fog that I took it off after a few days and decided to try again in the 2nd half of my cycle. I wore it the week before my period again and that's it.

I know if you're on estrogen and have a uterus, you need to take progesterone to counteract the uterine lining impacts, but what about taking progesterone without estrogen? I've listened to a few pods and googled this, and can't find a clear answer. The progesterone seems to be helping a lot. I'm not sure I need the estrogen yet, it's giving me crazy side effects, and with the patch shortage I'd rather leave it to women who truly need it. If I take progesterone without an estrogen patch, do I need to cycle it or only use it in the 2nd half of the month? I'd prefer to use it daily with the benefits it's had so far.