Advise needed for Mazda 6 2015

I bought this car 2 years back valued at 9k euros. Since then I haven’t had much trouble. I have been servicing it regularly and had maintained it well. But a few weeks ago came the biggest disappointment, my car gave an engine light saying low oil pressure. I put the car aside and I couldn’t start it afterwards, upon towing it back to the house and checking with the local garage, they informed that the engine has been seized , asked for 6k-8k for engine replacement/reconditioning. Obviously that’s closer to the car value itself so I denied it. The scrap value for this now is 500. I went to a different garage in croom, who might take almost close to 4k for the repair. My car is still sitting there as he will work on it after a week or 2. Currently I feel like I have done a bad investment. I want to get a new car but i need money for deposit which i don’t have. But im worried about the car i have as well as it’s probably gonna give me more problems. It has 183000kms on it right now. I am really confused on what to do. Please help me. What should i do?