I have eaten enough food. The food was delicious and may be I have eaten a lot more than required. I enjoyed it. Now I am very happy about it. How to describe this? Should we say "I have had enough food/ satisfactory meal" or should it be "a decent meal". Somebody suggested me "bellyful" which I don't think is right in this situation because 'bellyful' talks about only quantity. Please suggest right vocabulary.
I think the word you are looking for may be "sated": https://en.oxforddictionaries.com/definition/sate
Satisfy (a desire or an appetite) to the full.
...you could use "satisfied", but sated is just a bit stronger.
Just to add that the above would describe your state after such a meal e.g. "I was sated after the delicious meal". However, if you are looking to describe the meal, an adjective like "sumptuous" would imply both quantity and quality, while a noun like feast or banquet would augment this.
Sumptuous: Splendid and expensive-looking. ‘the banquet was a sumptuous, luxurious meal’
So, combining all the above you could say:
I was fully sated following the sumptuous feast you prepared for me.
satiated - To satisfy (an appetite, for example) fully. [The Free Dictionary]
I like to employ this after a good meal.