"Awesome" and "great" in the ways you're using them here are what are called in linguistics/grammar/lexicography an "interjection" or an "exclamation". Wikipedia says about these that "it occurs as an utterance on its own":
In linguistics, an interjection is a word or expression that occurs as
an utterance on its own and expresses a spontaneous feeling or
However most dictionary definitions say that it CAN stand alone, implying that it doesn't have to.
(Grammar) a word or phrase that is characteristically used in syntactic isolation and that usually expresses sudden emotion;
expletive. Abbreviation: interj.
Collins English Dictionary
Abbr. interj. or int.
a. The part of speech that usually expresses emotion and is capable of standing alone.
One common interjection is "Yes", so let's take the example sentences:
Yes, I'll do it.
Yes! I'll do it.
You'll see that in the first example "Yes" is a response." In the second it's an interjection expressing an emotion. Almost the same as saying "Awesome!" or "Great!". There's no grammatical rule prescribed I know of that stipulates the condition that an interjection can't begin a sentence and precede a comma. But don't you think these look better:
Person 2: "Great! Thank you for all of the help."
2: "Great. Thank you for all of the help."
If you're chatting or being informal in an email or something, there's no problem anywhere. Some people may object to joining the interjection with a comma to the main sentence if their switch is set to pedantic mode.
One case where it's not only acceptable, but kind of necessary, is situations like this:
"Awesome!", I exclaimed with excitement.
However that's a quotation and quite a different thing.
So in other words, consider the formality of the context, who you're typing or writing to, and consider what looks better on the page/screen. I'm not telling you it's right or wrong, but hopefully this gives you some perspective.
Also, I'm reminded of a certain sitcom episode, and obliquely relates to this:
Seinfeld, exclamation point