Definition: Given a real-life anecdote of a complex ethical situation, generate a suitable title that describes the main event/root cause of the situation. Imagine that the given text is a social media post, and you have to write the title of the post, so the users can decide to read the main text or not.
Input: A month ago, I had to leave my apartment and asked my sister to let me stay at her spare room until I found myself a new place. We decided I'd pay her $100 for what I thought would be a full month to help with the house bills, $50 at the beginning and then $50 at the end of the month. At that moment, I received my full monthly payment and had the money to pay, but I figured I'd be well off to pay at the end of the month given the low rent. We had problems with the internet too so I suggested to just get a new service and offered to pay for the first month.

After a week, I wanted to just leave her place because she was messy, never cleaned, my room was dusty and it gave me allergies, and she would always stay up partying in the house. I talked to my dad to let me stay at his place instead, since I needed a quiet place since I was going through quite a stressful period. I told my sister I was leaving, and I told her I'd still pay her the $50 I owed her and the internet bill. That was my mistake.

Last week, I was finally able to find a new place, and I had to spend a bunch of money to pay for the fees, the deposit and the first month's rent. My salary is not high, so I was left with around $200 for the rest of April after paying for everything.

A few minutes ago, she talked to me, and asked me if I'll be able to pay the $50 and the internet. I answered I only had enough to pay the $50, and she could tell me when the internet bill was up and I'd pay then, because I didn't have for both at the current moment. After sending the $50, I ask her when the bill is due and that I have a tight budget this month so it's hard for me to give her the money for that too. I thought she would understand and say it was okay with what I had already sent, but she instead tells me I can just give her the money next month. I was shocked at her reply. I just asked her again when she needs to pay and how much, and I'll try to see if I can squeeze it in right now because next month is just going to be the same. She said she'd tell me later.

I had every intention to give her the money initially, but right now, it's just not a reality for me without either cutting from my monthly budget or taking out money from my savings. I feel like I already paid my rent and the internet with the $100 I gave her, considering I only took showers, and used my room's light at most. I didn't even eat her food or used anything else too much to make her bills go up in a month, so it feels like overpaying. I know she needs the money, but I'm in a tight position too, and I feel like she doesn't see that and is only thinking about her own needs. I'm waiting for her to tell me when the bill is due, so I can tell her I really can't pay for the internet this month or ever, but I feel guilty and I'm scared she'll get mad and snap at me.

Am I the asshole for not wanting to pay her the ~$40 she is still asking for?

Converted currency to USD btw.

not wanting to pay my sister a full month's rent if I left after a week