To all of those seeing spiders, I think it is a spiritual warning. I don't understand it completely, but the first time I did this, waking to actually see a spider, scream, tell my boyfriend, jump out of bed, then be unsure of what happened, was about 10 years ago. He is a very clairvoyant, clairaudient atheist, if that makes any sense to you, and he finally told me, "...I think your spiders are me". I'm still not sure what he knew, but sure enough, it only happened when he was around, and once we broke up, they went away. I broke up with him because he was depressive and negative. Just now, the reason I found myself on this site, I woke up to another. I screamed and jumped out of bed and turned on the light. it took me a while to regain myself. I then looked at my phone, ringer on silent. A toxic person, who I would consider a rapist and unstable, whom I was barely dating before I realized this, had texted to say he was coming over to bring me my necklace that he conveniently put in his pocket when I told him to leave my house and never return. He had called me several times, just minutes before I woke up, at 145am. surely he was at the door, or snooping around...ugh...so scary. Everything is locked. There have been other occurrences in between that I don't remember as clearly what I was going through, but that ay the time also convinced me that this type of spider represents a toxic person, or possibly spirit. stay away.
Symptoms like yours can be caused by some meds. Low oxygen to the brain in the case of sleep apnea can cause hallucinations and/or bad dreams, as can other sleep disorders. Difficulty awakening can be anything from being awakened during deep sleep to having such disturbed sleep one is not rested. Being disoriented briefly on awakening can happen if you wake up during a dream.
A sleep study is your best option to get answers that are more than a guess.