I've been holding onto my past for so long. I don't think going to a psychiatrist will be able to help. What can I do?

Go!!! As long as you are above ground and sucking in air, there is the possibility of change. Make an appointment with a board certified psychiatrist today!
RISK. THE PAST MAY BE THE BASE OF DIFFICULTIES IN THE PRESENT. ALSO, THERE MAY BE CONCERN ABOUT ANOTHER PERSON KNOWING. IT MAY NOT BE AS DIFFICULT AS IT SEEMS AND A GOOD THERAPIST SHOULD BE ABLE TO HELP YOU WITH IT.
You are doubtful. It sounds like you are stuck/ obstructed by your past. You can stay stuck or do something about it.
Hugging a porcupine . Is not a good idea. It sounds like your past is troubling you so why not find a way to let it go? You don't necessarily need to see a psychiatrist. A psychologist, counselor or well targeted professionally run group can work. Don't wait. Go get the help in the way that fits you best - but go get it. Stop hugging all those porcupines. It hurts.