I don't know what I should do and this website is basically what goes for my social support system these days, so I'd like some advice please.

So I drive a very old car that until recently I didn't use much. It's from 2003 and it has less than 150k miles on it. It has a check engine light that I learned today comes from a tiny crack in the (a?) cylinder head gasket that's causing me to lose coolant. They quoted me 3-4k USD to replace it.

If they said 2k I might have been able to melt my debit and credit cards at the same time MAYBE. But 4k I need a loan for.

It's possible that this place is just a ripoff. I'm partially just talking this out right now so I should really get on the phone and find out if I can find something that won't break me.

Part of why it seems like it might be a ripoff is that I can find the parts (according to my completely uneducated and untrained figuring) on autozone.com for like 250 bucks. Maybe I can just do it myself? Maybe my landlord has tools? Or I can rent some maybe?

The guy at the car doctor said that if I wasn't going to do the repair I should probably trade it in sooner than later while it still holds value. Down this path I might really start crying about needing an adult though. A whole branching tree of decisions to make afterwards.

And to bring up an added complication: part of why I don't have a solid chuck of the downpayment of a house on hand to deal with this is that I was semi-homeless up until three months ago (friday is the anniversary). A downstream complication to that is that I never received my auto registration renewal from the state of CA. And by the time I realized it was a thing I should have had to deal with already, my shit expired. I'm pretty sure they're going to make me do a smog check which requires that I don't have an engine light on. So it's extra fucked to be driving with it right now. Oh and my insurance dropped me over a dispute over late charges I refuse to pay because they didn't tell me I owed them money and sent shit to the wrong address over and over.

So I guess an informal poll:

A: I shop around for a mechanic that's willing to fix my cars for the clothes off my back + fill up my credit card again ( T_T ) IF I CAN FIND ONE (and if not I guess take out a loan)

B: I buy the parts/find the tools and see if it's possible to do it myself, on like, a weekend.

C: I throw in the towel on my car and try to find a replacement somehow despite being broke enough to be here

D: Something I'm not thinking of.

I fucking hate this. I hate cars. I wish I could bike. I wish I could take transit. I hate having this single point of failure in my life that can completely sweep my still shaky legs out from under me, which I just now finally got up onto. I need advice because this decision could literally be the fucking end of the world for me. Yay.

edit: the specific car is a 2003 Suzuki Areio