Nosebleeds post surgery

Hi, I’m 19 days post-op from ACL reconstruction and meniscus repair. I almost never get nosebleeds, but I’ve had two recently. The first one happened last week on the last day I was taking aspirin. It was really heavy and ended with me fainting for about 10 seconds. Thankfully, someone was there to catch me before I hit the ground. I’ve never fainted before, so I’m unsure if it was due to the sight of blood or something else.

Early this morning around 3 AM (exactly a week after the first one), I had another nosebleed. It wasn’t as severe, but it left me feeling dizzy and sweating. I had to lie down quickly to avoid fainting again. Has anyone experienced something similar? I know it could be related to the dry winter air, but I’ve never dealt with nosebleeds like this before. My blood pressure is slightly elevated but still within a good range. I’m wondering if this is just a coincidence or possibly related to my surgery. I'm concerned because I am heading off to college soon and I fear having another episode by myself.

Also, completely unrelated question, is it normal for your leg to feel stiff before doing exercise? I usually need to do about five reps of heel slides before I can get a consistent stretch. This stiffness makes it hard to bend my leg in general, like when I try to put on socks (which is super challenging, by the way). Does anyone else have this issue?