well, we can always try and recreate the calm feeling for you - did you manage to get some nice relaxing music today while you were out or was it just to your appt and then home again?
i have just looked on Youtube for relaxation stuff for you and found this guided meditation for stress release and relaxation - there are a few there so you might find one that you prefer, or even just some relaxation music.
Have you done the "safe place" thing at all with anyone? This is something that is useful when you are feeling panicky or stressed up. You need to be in a fairly relaxed state to start with - then you think of a time and place where you were truly happy and felt safe. You concentrate on this place - see everything in detail, check the colours of what you can see, make it brighter if that's what makes it better or dimmer if that improves it.
THen you concentrate on the sounds that are associated with this place - listen to them in your mind, have them as loud or as quiet as makes you feel the best.
Then focus on the feelings in your body - the temperature around you, what you are in contact with, is there any breeze gently wafting over you - make these as pleasant as they can be.
As you concentrate on honing this scenario to perfection, allow yourself to relax, breathing more slowly and deeply. Then, when you feel the best you can, name this safe place with an appropriate and memorable name. Say it to yourself 3 times, each time in a deeper and slower voice. This helps to "set" the feelings and pictures in your brain, so that you can recall it at a moment's notice.
THen, whenever you are feeling panicky, scared, overwhelmed or whatever, you can say the name of your safe place and it will come to mind, bringing all those feelings of comfort, peace and relaxation with it, helping you to deal with the problems that arise.
This is the best I can do on MN for you - it is derived from genuine therapeutic techniques, not just made up stuff!