As the mom of a 9 year old who has a son like yours, I suggest patience. My guy finally got diagnosed in Kindergarten, but we knew before that about his anxiety/OCD tendencies before then. He is a bright kid - does extremely well with math and science, (loves science) reads at an 8th grade level and is very orderly. At night, every time before his shower, he organizes the things on our sink counter very precisely - one of his many habits like that.
When he was younger, he would line up his books in a very precise pattern. He had to have everything perfect, and would be very upset if things he was working on didn't come out the way he had tried. Sleep was rough - couldn't sleep (and still has trouble) if worried about an upcoming event. He would jump on his bed and when I told him he needed to stop, he would say "I have to jump 8 more times" because he needed to finish his pattern. He would have to put his shoes and socks on is a very specific order, and if someone tried to help him out of the order he wanted, he had to start completly over. He does not have autism - I recognize his traits because I am guilty of many of them myself. I understand his need to have everything "just right". This is his personality, who he is. Trying to change it will only make things a bigger struggle. Just use his strengths as much as you can, giving him reassurance and love (as I'm sure you are) frequently.
We did go through an anxiety program at Riley last year. It was helpful, but he was still pretty young for the program, so I don't think it would be a benefit for you yet - many anxiety programs aren't set up for ones so young - understanding the process is hard for adults, let alone little ones to grasp. I suggest you seek therapy if it causes great disruption in daily life, though. If he faces great frustration or feels very different from others, depression can develop. It doesn't automatically happen - you just might keep an eye out for any issues.
As he gets older, he will begin to figure things out in terms of how he needs to handle things in relation to others as well as himself. There is no overnight fix, just time and patience and learning. We have come a long way - and as parents we do everything we can to help our kiddos, but, as with many things, all we can do is help them learn and develop - it is ultimatly up to them - we just are their support. Good luck and know you have a very special little guy who is lucky to have a mom who loves him and is looking out for him!