Adjustment after diagnosis of 4 year old

My son has recently turned 4 and just received his autism diagnosis. I'd consider him to be quite high functioning in some areas - very good fine and gross motor skills, no major sensory issues, appears happy in loud places, very sociable, very good eater. During 'good' phases I don't see much difference between him and a NT child, but we regularly have less good phases and regressions.

The areas we struggle with are speech delay - this is improving and we are able to understand his wants and needs, but he is very repetitive and there is no meaningful conversation. He is also very emotional and will burst into tears over the smallest things, or scream at the top of his lungs when he's overwhelmed (this is a real trigger for me). He does pretend play but again this is the same game repeated over and over and whilst I do want to spend quality time with him, I find it difficult to go along with this cycle of play. He is often very loud and will shout and 'roar' sometimes for no reason.

As he's getting older I'm noticing more and more the differences between him and other children his age and I guess I feel worried he won't find friends who accept him when he starts school.

I realise some of the struggles are developmental and 3-4 is a difficult age, but I'm wondering if these things will improve over time or if his emotions will become more regulated. I'm hoping we will be able to enjoy our time as a family more frequently as he gets older.