I’m so tired

My LO is 6 months old. At about 4.5 we did cry it out method while transitioning her to her room and crib. She did amazing. She can now put herself to sleep for bed and nap. Sometimes she does feed to sleep but others she is awake and self soothe and settle. She was sleeping 6-8 hours straight and dropped to one night feed. We even got lucky 3 nights and she slept straight through without a feed for about 11-12 hours. Recently, for the last week or so, she has been struggling to stay asleep during the night.she has consistent bed time routine-bath, bottle and bed. She naps approx 3 hours and has done this for sometime. Waking around around 10-12 am 1-3 times, again around 2am- I’ll feed her then, around 4-7am about 2-3 times. She is unable to settle or go back to sleep most times while fussing and crying. I will sometimes go in pat her butt and give her Binky. She will go back to sleep to wake up in 5 mins - 1 hour. Is this a sleep regression ? She isn’t teething, during the day she is fine. She has sound machine, humidifier, black out curtains, I monitor the temperature… what could it be? Anything I can do? Running on fumes Schedule (approx) 6:30-7am wake and eat 9am eat/ nap- 40 mins 940ish-wake and play 11:30 ish eat/nap -approx a 1 1/2 hours 1-eat and play 3:15 last nap 45-1 hour 6:35 bed time routine 7pm sleep