Stuck with low gpa how should I fix it

I have a total of 526 Earned quarter points, and and 228 pt’s graded for a total gpa of a 2.307

Most Graduate schools require a 2.5 to get in on probationary terms. This is a result of me being in petroleum engineering and thinking that i’d have a job out of school no problem even with a 2.3. Obviously, I was wrong.

Do I onsider going back to undergrad for a year to just get some A’s and boost my gpa up to a 2.5? or do I try to find a masters program that will accept me, then transfer that a nicer masters program after I get my grad gpa up?

Unfortunately, I kind of have to be the wet blanket.
If you’ve graduated and finished your undergraduate degree, I see basically no way they will let you come back and take classes just to boost your GPA. I’ve never heard of anyone doing this and I’ve never seen any process set up to allow people to do this. Even then, a 2.5 is still probably not a GPA that would put you in consideration for grad schools.
But in my opinion, you shouldn’t lose hope. I would suggest you look into non-degree graduate programs where you can take graduate level classes at a university but aren’t working towards a degree. Assuming you do well in them, they act as evidence for a grad school you apply to to actually get a degree from that despite your poor undergraduate performance, you are capable of handling graduate level work and they should let you in. Some programs will let you count the non-degree classes towards your actual degree, but I don’t want to tell you that all of them will because I’m not sure.