My car started acting up yestrerday and the ecu is throwing these cels

1, o2 sensor
15, ignition output signal
43, fuel system

I know what they mean but does anyone have any ideas what I should do?

I just replaced my O2 sensor a couple months ago and I have one of those b&m
fue pressure thingys.

About a month ago my car just died on the way to work one day. i towed it home
and the next day I found that my main relay wasn't getting power from the ignition switch
so I have it rigged with a switch and 12v from the battery. I know its sounds ghetto, but
I haven't had time to fix it right until. now I'm going to have 12 whole days off work.

This is my daily driver, and I drive her hard everyday, b20's are mad fun but sadly
my 20 year old baby is showing her age. I tried to not think about it to much but
its time to face the facts. my chassis is in pretty poor condition. Its rusted pretty bad
i've got a big hole under where the passengers feet go, and on the drivers side and both rocker panels and i've replaced the rear sub frame that the lower control arms connect to because the spot welds rusted out and separated from the chassis.
yep, my car has terminal cancer

I'm wondering if I should even attempt to repair all this **** or find another ef and swap my b20 over to that? I would like to find another crx shell but I would take a hatch or a 4dr sedan even. My cousin has a 91 ex 4 dr with b18b and I kinda like the way it looks.
I don't know, I can't make up my mind