I assume you went to a public highschool. If so, you had to file notice with the school district within 90 days of the alleged wrongdoing. You may apply late with Supreme Court permission if you have a case and there is no prejudice to the district, as they are responsible for the counselor. You may get an extension for infancy up to the time you turned 18, if you were not 18 when the wrongdoing occurred. Consult a tort attorney or and eduation attorney. Of course, this all assumes there is a cause of action for the bad advice/bad scheduling.
If you found this "helpful" or "best answer," please click it with my appreciation. My response is for educational purposes and does not constitute legal advice nor creates an attorney client relationship which requires all the details and a personal conference.
FYI, don't put too much stock in the teacher's advice about what makes a good case. Odds are you have no case, as you likely signed paperwork at some point that explained the onus is on YOU to ensure you are meeting requirements for graduation. But its worth a chat with the right kind of attorney and I wish you all the luck in the world (wait until after the happy event before you try to pick this matter up).
READ THIS BEFORE CALLING OR EMAILING ME: I am licensed to practice before the state and federal courts in Virginia. We have not established an attorney-client relationship unless we have a signed representation agreement and you have paid me. I am providing educational instruction only--not legal advice. You should speak with an attorney to whom you have provided all the facts, before you take steps that may impact your legal rights. I am not obligated to answer subsequent emails or phone calls unless you have hired me. I wish you the best of luck with your situation.