dolly56 Oh bless you! As so many have said here, I too understand exactly how you feel. Once a very frightening event has happened it stays with you and you cannot help but worry about how you would cope if it happened again, especially on holiday.
I think if your DH were to be ill while you are away in your caravan, people would all help you and the help he would receive would be the same as if he were at home. Nobody would expect you to tow your caravan home or do anything difficult. People always rally round and help in a time of emergency such as this. Try to "let go and trust" as a friend of mine who had chronic anxiety told me.
There are many of us who understand this feeling of impending doom and terror that you have. It really would be worth discussing it with your Doctor. The events around your DH's illness may have left you a little traumatised and you deserve some help to get through this.
Please try to trust that that if the worst happens then people will help you and you will cope, we always do. But most of all, keep things in perspective, the worst does not usually happen! No doubt your husband is now taking better care of himself, or is on some medication to prevent another attack. Try to live in the moment, enjoy the lovely things happing right now, the smell of roses, taste of coffee, beautiful view, comfortable bed, good company... Give yourself permission to indulge in what is happening that you enjoy and immerse yourself in lovely things.
Wishing you a very happy future and that you feel stronger and more confident each minute. With love, Elle x ???