Hello, and welcome.
I'm so sorry to hear that Loki fell and hit his head and then injured it again, when he ran into the coffee table, trying to get under it.
If his pupils are dilated and he seems to be having vision problems, plus, he's sleepy, it does sound like he may have a concussion and this needs to be diagnosed and treated by a vet, immediately.
If your regular vet is not open at this time or doesn't have emergency hours, bring Loki to the nearest ER vet center for evaluation and treatment. A traumatic head injury can be quite serious, but, if caught early, hopefully, he should do well.
Try not to let him fall asleep and rush him to the vet, now.
I hope all will be well with Loki and please let me know how he's doing and what the vet tells you. Thanks!
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