I'd like to thank you for the whole time we spent together, for your great care and effort you put and for the almost 2 fabiulous months.
I'll never forget what you've done for me, that time I would enjoy spending with you and everything you've done for me.
I'm really sorry for trouble I've made during my stay.
Apology and Thanks from my parents who want to render the best for you, too.
Ok, the last version is close and I can work with it. This is how Id write it and Im a native speaker: "I'd like to thank you for the time we spent together and for the care and effort during the 2 fabulous months I was with you. I'll never forget what you did for me nor will I ever forget enjoying being with you. Im really sorry for the trouble I caused during my stay.
Thanks very much and I hope you can accept my apology. Thanks also from my parents who also wish you the very best.
Perfect :)