I have a 7 1/2 month old and I have been seeing a physio for him for a few months because of his flat head shape.He has also struggled to have tummy time and always wants to stand rather than sit and is quite stiff also. He has just started rolling in the last couple of weeks - and is starting to get the hang of sitting.
The physio was really helpful, reassured me and gave me lots of good ideas of how to help him and exercises to do. It took a while for my little boy to catch on though, but he's getting there now. We have follow up appts every 5 weeks. Don't worry too much - I found the whole thing great, even though I was very worried at first.