HT,Good Morning my friend; it does my heart good to know that we have been friends here in the forum since the day you joined 5 years ago. I have watched you meet challenge after challenge and yet you do not give up.
I think perhaps it is time for a bit of Kitt's reminders - you know how I love positive quotes so let's start today with this one:
“Three things in human life are important: the first is to be kind; the second is to be kind; and the third is to be kind.” ~ Henry James
Being kind to yourself in everyday life is one of the best things you can do for yourself. Life will become lighter and your relationships will most likely improve. You will feel happier overall. And your self-esteem and your sense of deserving good things in life will go up.
But it also is one thing that we often neglect or feel guilty about doing for ourselves. I am going to ask you to do one act of kindness towards yourself today.
If your day feels mediocre or just sort of depressing then take one small step towards something positive to breathe new hope and optimism into your day.
Like you, HT, when I do not feel well I start to worry which leads to "what if?" thinking. Believe that your trip will happen and you will have the time of your life.
I used to try to plan my trips hour by hour and would spend way to much time in the planning as well as stuffing my suitcase with everything I might need.........I now make a list of what I have to do as well as what I truly need to take along with me. I post my list on the refrigerator several weeks before and bring my suitcase up ----------I will rework my list by questioning if all the things on the list are essential for this trip or are they in the "what if?" category.
An umbrella - what if it rains? Really ??????????? If it rains I will deal with it at that moment in time.
The most important things are at the top of my list...........passport, funds, reservations, airline itinerary. On my list I note where I have placed these items in case my brain fog kicks in and I cannot remember, I don't have to get stuck in high anxiety, tearing my house apart worrying about "what if I can't fine it?"
Keep things simple. I am the lady who went on my first cruise and forgot to pack her underwear..............so each evening I washed out my one pair as cruise ships and exotic islands don't sell "granny panties" LOL Good thing it was a 4 day/3night cruise. 
If you stumble, be your own best friend. Don’t beat yourself up, that will erode your self-esteem. Be a kind and supportive friend to yourself instead.
Ask yourself: How would my friends support me and help me in this situation?
And then do things and talk to yourself like he or she would.
And remember to ask yourself what you can learn from your stumble and if there is an opportunity in this situation. Then take that new knowledge you gain and move forward once again.
I will be keeping you in my prayers that you begin to feel better - if you need to, call your Dr. re how you physically feel.
I believe in you! I am glad to have you as a friend.
Blessings,
Kitt