PerfectPeony2 - firstly please don't worry, most of the time things can mimic and look like things to worry about when they are totally normal.
However, having said that, I knew at 4 months old that my son had something different going on. My sister commented on how when excited rather than the typical hand waving smiling and giggling a small baby makes, my son went rigid, with pointed hands and feet. It was obvious enough for me to video it. However I was dismissed by others as don't be stupid you can't see autism that early. As a consequence I dismissed other signs, and was told by a CAMHs psychiatrist when my son was age 9 that it can't be autism as he makes eye contact. I believed them, and it delayed diagnosis by another 3 years. My gut instinct was right all along, and when the diagnosis was made, so many who knew my son pointed out reasons why they "knew"! What I am saying that whilst in all probability you are seeing things that are normal, don't doubt a mothers instinct!
Scanon - my son was told that he made too good eye contact at age 9, it delayed his diagnosis by 3 years. One bit of advice that came too late for me was to request that the paediatrician put in writing the reason that they don't think it is autism.... they will not be able to do this, and this can be your lever for requesting a full formal assessment.
Whatevermission - have you sought help for sensory issues with an occupational therapist? Understanding sensory issues can really help with reducing anxiety.
I remember for me school was really hard mostly due to the school uniform irritating, and not being able to tolerate the noise (fortunately I had temporary hearing loss, glue ear, through most of it and was given hearing aids which I left in my ears switched off!). But I never voiced these at the time, as I did typical masking and trying to copy everyone else. I only got my diagnosis last year, way too late! I was always "different" from my siblings, but never understood why, until I saw myself in one of my children, the one I knew to be autistic!