Please help me to save my cat

Hello, I hope everyone is well. I would like to ask everyone for help because my cat Dante is having a serious medical problem.

Dante these last two days has been having bladder problems because he hasn't been able to poop properly and aside from that he's been vomiting everything we give him to eat, the truth is I didn't worry because he still has a lot of energy and I asked the people I adopted Dante from, they told me it was because of the type of food so I changed him to the food they told me about, that was on September 20th, but that same night when I got home from work he started vomiting a lot worse and I decided to take him to the vet today, September 21st at dawn, they told me it could be for many reasons, for example an obstruction or liver stones. In order to do the procedure, they asked me for approximately 2000 dollars and right now I don't have that amount of money. I know it's a lot to ask but please I need a little help from you. Thank you very much for reading this and I hope you have a nice day.