Just got extreme apnea. What do I do?

I've had my fractured leg in a cast for 6 days. I've been doing anti thrombotic belly shots daily because of that. Yesterday I started feeling off, a little lightheaded my heart rate was 120-130, blood oxygen was 93-95. I went to the ER, d dimers were 0.44, they also did a ct angiography which was clear (no embolism). This whole thing lasted like 8 hours. Then I slept normally at night. Today I woke up at 8 am and at like 2 pm was kinda sleepy, tried to get some sleep but the moment I started drifting off I stopped breathing, "woke up" taking a deep breath (gasping most likely). Measured blood oxygen, it showed 91-92 then after like 5 secs went back to normal. And it's been like that since (it's 1 am now) the moment I drift off to sleep my body stops breathing, I "wake up" gasping, my heart feels like someone jumpscared me, then after 1 minute the same thing happens. Wtf do I do? This is seriously the worst experience I've had in my life and it won't go away. I'll probably go to the ER again but I'm afraid they'll send me home.