You don't say how long it is until your friends will be arriving. If there is enough time, you might consider taking a day or two, just for you. Go somewhere you have been wanting to go; do something you have not taken the time to do. Find a way to relax and take your mind off these things. You might think of this as wasting time, but it just might be a good way to help clear your mind, and even better if you can actually get away for a couple full days, such as a weekend somewhere.
Perhaps you can find a friend or relative to help you prepare your home, so the pressure is not all on you.
Is there some way that you can reduce the stress at work? Sometimes, we work so hard, we don't sit down and figure out ways to make it easier. Are there any other people where you work who can share the load? Are there any ways to make it a bit easier on you?
Make sure you have your health checked out. Sometimes, high blood pressure can cause problems. Additionally, some other heart problems can actually cause anxiety attacks, such as atrial fibrillation and possibly other health issues, too. Do make sure you check out and take care of your physical health. If you are going too fast, too much, too long, it will affect you in one way, or another. Take a break. Get a check-up. Take care of yourself.
Try cutting out caffiene or products with this in them, sugary things, etc. This may be contributing to your difficulties.
When your friends come in, try to think of what things cause problems for you: are you more comfortable while inside with them one-on-one? If so, then try to spend more time doing things like this. If you feel more comfortable in situations away from the house, then try to schedule a few more things that involve going places that you will all enjoy. If you are worried they aren't going to have fun, again, take the burden off yourself and just take it as it comes. They will need to do the same.