I own a Volvo 01 S60 T5 turbo.200,00 miles. I had battery and alternator replaced. Prior to that moment my car had been acting pretty weird at times... One day for example I was leaving my college as I turned the key the car started and was very rough idle and high rev and it would shake and die out.. i suffered this over and over for about ten mins..I could smell gas inside of my car. Very strong. While also around this time I noticed that at random moments while driving high speeds (45-70) and giving it gas my car would jerk or sputter.. after while my car became hard start at times.. but it would start.. as if it lacked fuel pressure. fast forward to after changing alternator we started the car and It idled smooth nothing out of left field.. but the moment I drove down half my street the car starts shaking really hard.. I couldn’t drive over 30 and it worked it down to 20 and never should drive over it.. Engine was misfiring and exhaust was making loud noise but no smoke.. car was running very rich or lean but I could smell Fumes.. my neighbor is shade tree mechanic .. he’s pretty good. He ran codes from his scanner gotten nothing first time.. he checked some forums and decided to order a throttle body and I order new ignition coil packs and brought spark plugs.. new fuel pump & new fuel filter.. New MAF sensor.. car idled Little better. Hard start was over. It cranks with no problem now... but still surging & high rev in park ,engine misfiring, can’t drive 20, slow to Accelerate still.. lack of engine performances. we eventually got codes and as following P0351-P0352-P0354-P0355-P0353-P0121-P1550. My neighbor read the codes and double checked all the ignition coils.. As I mentioned after I placed the fuel pump (clogged up) fuel filter ( very clogged black gas coming from it) it idled better and no more hard starts but still other symptoms . After checking all checking under hood for leaks or faulty lines we found a few that were worn we placed them.. the most recent codes are P205 & 206 as well P351&352.. P121 and P1150.. We found that inherit aren’t firing to cylinders so I recently ordered fuel injectors.. almost for got I found oil on top of valve cover ? I’m not sure what to call it but yes oil while changing spark plugs.. Also after I change the oil.. the oil still appears on the dash board.. I don’t understand Please help me.

Been with a car for 4 months and It’s really depressing. I’m a college student taking up my nursing major. BSN. Thank everyone who will reach out to help in advance.. Blessings.

P.S I’m getting broke and really need help... worst of all I’m stressed of not having transportation for school in one month..