Hi op, another huge hug and cuppa here! Honestly what you’re describing is totally valid, I’m a couple of years ahead of you in the SEN journey and I still have waves of sadness and grief.
I couldn’t agree more with what @IanCurtisdancing has said. Find a nursery with a great SENCO, advocate for your son because you know him better than anyone else, other SEN parents have been a godsend to me.
My son sounded incredibly similar to yours, pecs cards are fantastic for no/limited eye contact, we started slowly and introduced a few cards during meal times… they’ve been a lifesaver and he picked it up within a few months. This meant he could communicate with us and then slowly his language has started to develop. He can say lots of single words like counting to 20, colours, animals, his favourite food/book/toys/tv program… he’s started to but two words together now which is a huge milestone for us. Oh and his eye contact is “normal”
Another things I’d add is applying for DLA, I was really hesitant at first (I assumed it was means tested) but I wish I’d applied for it sooner, it ended up paying for private speech therapy, as there was a two year waiting list for an NHS SLT. Nursery can also claim funding for extra materials/resources for your son, and it helped financially as I can only work 20 hours a week due to my son’s reduced timetable.
Above all, remember to be gentle with yourself. It's okay to grieve the life you thought you'd have and to feel overwhelmed. Take each day as it comes, celebrating the small victories and seeking comfort in the love and bond you share with your son. You're doing an incredible job, and there's a community here ready to offer support and advice.