Dealing with guilt-tripping mother... Any advice?

Hi all. Here is my situation that I could use a bit of advice with. I am 37 and am an only child. My husband and I live less than 10 minutes from my parents. My mother is almost 73 and my dad is 80. They struggle quite a bit financially as they live solely on monthly social security benefits. My husband and I have always helped them as much as we can, but it has been more and more frequent over the last 4-5 years.

In 2013 or 2014, their only vehicle died and they could not afford to buy a new one. My husband and I had 2 SUVs, but since I work from home full-time, we really only used one of them. One of them we had just finished paying off and the other one we were still making payments on. When their car died, my parents asked if they could borrow one of ours, to which we said yes. We gave them the one that was paid off. A few weeks later, my dad called me and asked if they could borrow it "indefinitely," meaning that it would stay at their house for them to use, but it would still be ours and we could use it anytime we wanted. My husband and I agreed to do this. Well, about 6 months later, while my dad was at a stop sign (it was snowing), when a truck came flying around the corner, hitting the front end of our vehicle, causing significant damage. Thankfully, my dad was not hurt, but the vehicle was a 100% loss. The other driver's insurance paid us what they deemed it was worth, but it was not enough to buy a new vehicle outright. My parents constantly hounded me about getting them a new vehicle, which would mean that we would have to take on a new payment. At one point, my father even said to me, "If your mother and I don't have a vehicle, we may as well just roll over and die."

That spring, my husband and I went out and bought ourselves a new vehicle (we financed it) and gave my parents our other vehicle, which we have been making payments on the entire time. Thankfully, we only have about 6-8 months worth of payments left on it. On top of that, we also pay for my parents' phone service and have them on our family plan. We help them with food also.

The issue now is with my mother and her incessant guilt trips. Last week, she was telling me about how their cable services were going to be shut off because they can't pay the bill until they get their SS checks on the 3rd. Later that day, my mother texted me and asked if we could lend them $50. She said if we could do that, then they could just overdraft their bank account to pay the cable bill. We gave them the $50. Well, a few days later, my mom texted me and said that the check they used to pay cable will actually NOT clear, so they will still be shut off. I said I would see if we could help pay some of it, to which she replied, "Oh, no! Don't you worry about it. We will be fine." A few days later, she texted me in the morning saying, "Hi. How are you? We are just sitting here waiting for our cable to be shut off. We went to the food pantry and all they gave us were noodles and black beans, but don't you worry. We are fine." I responded by saying, "Do you have any idea what it does to me when I wake up and see texts like this from you?" She then apologized all over the place. Then, this morning, I woke up to a text from her saying, "You won't believe what I did. I broke the new coffee maker you got us. I feel horrible. I lifted the top and it got stuck under the cabinet and snapped off. I'm so sorry. I know it was expensive. If you don't want to talk to me ever again, I understand." She then told me how she had been crying about it all morning and said they now have no way to make coffee. I said we couldn't replace it right now, but she said, "No! Don't worry about it." However, I KNOW she wants us to replace it.

She always does this pity party/guilt trip with me.

I can't take much more. She is getting worse and I feel guilty for being at my breaking point, but I am starting to feel resentment. I worry about them enough. Any advice?