Other mums will understand, do you have any vague contact with anyone you used to meet socially?
Because I bet if you contacted them (maybe not today but this week) asking how they are and they would like to meet you for a coffee, they a) won't care you've not been in touch because b) they'll've done the same and c) they'll be delighted you've been in touch.
I have had many mum's with young children 0-7, apologising for not having been in touch. I text back, I know! I've been there, sometimes a week will go by and you think it's only been a few days.
And if not, set some time out for yourself. Teens are selfish, yes, but they will appreciate boundaries, and need them, despite what they say (most words of anyone aged 13-19 said in anger mean absolutely nothing, and they regret it almost immediately).
When you make some guilt free me time, that's a boundary, when you talk to her about how disappointed you are at her carelessness, that's a boundary.
I know you suspect she bought the vape with it, but I would disassociate that with the money. So the third boundary would be the vape, she's too young to have bought it, her health is too precious, where did she get the money from for it potentially? (Job? Pocket money?)
As for your mom, is this demanding for Mother's Day usual? If you have put up with it for today, from tomorrow, begin with boundaries with her too. If she needs you, she doesn't need you immediately, she can wait, and maybe solve her problem first.
I assume you work? If so, and your mom's needs are such she demands so much of you, tell her that she will need to call on someone else to help her when you are at work, including the time it takes for you to get your workplace, your breakfast, including your lunch break and including time to get home and unwind. You can't multitask and be on call.