My ds is now 11 - will be 12 in April and also has Aspergers. We had big problems with food when he was younger. Refusing to try new things, some foods he simply wouldn't entertain, usually due to the texture, rather than the taste and some, chocolate included, that he couldn't even bear the smell of. At your ds's age he basically lived on pasta and cheese sandwiches. (Not great since we later discovered he can't tolerate gluten.)
We just worked around it. Every now and then we'd try offering a new food, but didn't push it, as we were fed up of mealtimes being a battle. We found maybe 6-7 meals he could eat - which were all basically different ways of cooking the same constituent parts - and rotated them.
He gradually improved over the years and as he got older and wanted to fit in more, was more willing to try some things. He's gone from not eating any form of potato, to trying chips and liking them, then attempting one roast potato each Sunday to now liking half a plateful. He still won't even attempt some foods, but has learned to cope when others eat chocolate near him.
I do think some of it comes out of maturity and some from wanting to be like their peers and fit in.
My ds is also highly emotional. It has been said about ASD that, contrary to what many people believe, it isn't a lack of empathy or emotion, but rather too much emotion that can result in overload and/or shut-down and that describes my ds perfectly.
Again though, he has learned to manage it more as he matures and at nearly 12, he manages his emotions much better. He still cries more easily than his peers, but has developed coping strategies so that he doesn't get teased for it. We did a lot of work around learning to scale his emotions to help him recognise that not everything is the end of the world and get some perspective on how good/bad things really are and that has really helped. There is a book about using feelings diaries for ASD on Amazon and there are quite a few on emotional scaling. We didn't use them ourselves, but someone else on here should be able to recommend a good one.
I do understand your worries re secondary school, I was just the same, imagining him bursting into tears all the time and ending up teased/bullied for it, but he started in September and it hasn't been like that. He matured quite a bit in years 5 and 6 and my fears for him re secondary when he started the juniors were mostly unfounded. It's not exactly been a smooth ride, but the things I was worrying about when he was 7 have, for the most part proven to be unfounded.
Keep posting, there are lots of people on here who have children who have ASD and there's a wealth of knowledge, support and strategies to share.
Ps, come over to Special Needs Chat and join in the weekly chat thread at the virtual Goose and Carrot pub. It's where a lot of people from MNSN get together to whinge, cheer, commiserate or celebrate whilst sharing virtual 
cake and chocolate. There's a new thread that starts every Friday evening, but then it runs for the whole of the next week. The current one is here.