Well, it's been a long time since I've been pregnant...but I am an anxious person myself. Some of your worries are typical/normal. I also remember feeling a little freaked out if I sensed that movement had slowed down or wasn't what I thought it should be. I think that's normal.
I can tell you to relax and don't worry, but it's obviously not your nature.
Just try to keep a few things in mind:
You don't have any high risks (such as placenta previa).
With a healthy pregnancy, such as yours, the female body can do all sorts of things and handle it. Heck, at 9 months I was chasing my dog through the neighborhood at a sprint as she was loose. Millions of women work physical jobs through their pregnancy right up until they end and they are fine if they have good health to begin with. You can do "normal" stuff such as moving light furniture or boxes.
Finally, realize that your are likely feeling anxiety here because this is a situation that you CANNOT control. It will be what it will be. Your thoughts are really about control and the loss of it. Choosing not to do physical things or doing them and fretting about it is an attempt to control the life of the baby--you can't. Just live normally and sensibly and try to let the worrying/control go.