Answer:
Yes but don't
Explanation:
It completely depends on what you are saying. "At all" is usually used in negative statements like "you can't cook 'at all'" but it is possible to use it positively. However I would play it safe and just not use it when talking positive.
I cant do that for you,but i can tell you how: tell them how they have inspired you and what you like about them, recall a situation where they helped you emotionally, and tell them that you appreciate them and that you are sorry. put in alot of inspiration and empathy/sympathy. dont like, copy anything because they could tell if it sounds like you or not and that might hurt them more. Good luck .hope this person feels better.
They function as an adverb, I guess you can say.
The answer should be true :)
