bu- but think about it

Why IAH, DH or IWH probably won't work:

(For speaking purposes) Try saying them out loud. Try getting used to the feel of them. It sounds odd, no? Also, when one uses abbreviations verbally, they are often used as part of a sentence, for example, "______ sure cmi". IAH and IWH are independent clauses in themselves, and hence it makes you sound immensely retarded when you say them. DH, on the other hand, stands for 'damn hungry' which is a phrase. However, because it has two letters, it doesn't sound as fluent. Try saying "I'm DH!!!!!" Wait, let me cover my ears first.

(For writing purposes) Admittedly, there are abbreviations so frequently used that they are shortened, which are not meant to be spoken. Classic example: ikr. However, contrary to popular belief, phrases 'I am hungry' or 'damn hungry' or 'I was hungry' are not as often used. But for argument's sake, let's assume they are. Let's consider their impact versus their non-abbreviated versions:
"IAH ):"
"I am hungryyyyyy ):"
I'm sure you will agree that the latter sounded more sincere and impactful. This is because, unlike phrases like 'I don't know' or 'I know right', 'I am hungry' is used to make a point, and abbreviating it just ruins it.

A third reason, which I think applies to abbreviations meant for both speaking or writing, is that besides having three letters, is that they shouldn't have two vowels next to each other, like 'iah'. Think of all the abbreviations commonly used: idk, ikr, cmi, imo, fml, mmd, and so on. Few abbreviations manage to pull it off - the only one I can think of being lmao - and combined with the two minus points I'd mentioned earlier, IAH (and DH and IWH) probably cmi. (I realised this point is not very strong and that the only reason why two-vowels-together won't work is because we're not very used to them.

So anyway, that's why IAH, DH or IWH probably won't work. Although we should come up with more abbreviations! (Eh, ThinkOrange don't be sad D: )