i hope all went well today with you appointment
just wanted to add a late post to maybe reassure you a little bit and say i was the same with my DD (8mo) at around that stage. she went very quiet and distant and she also did strange screaming, staring into space and going suddenly rigid for a few days. i was worried absolutely sick and googling just made it worse - everything is a symptom of everything in babies, it seems
just as i was about to make a dr's appointment, a friend came round and when i told her my worries and told her to look, she went "yeah, she's just being a baby" and told me all the odd twitches, quirks etc her daughter has
i think the things that worry you sick as a mother really often can turn out to be nothing - with hindsight, i guess she was strengthening her muscles or something. in any case, soon after, she started sitting independently, started babbling again and was right as rain.
anyway, thinking of you, as i know how it makes you feel when you're worried like that