Hi Beyond - my mum was adopted in the 1940s. She was just a few weeks old and her parents were unmarried. They were forced to give her up - against their wishes. Very sad.
My mum had a happy life with her adoptive family and didn't want to make contact with her birth family. However, soon after the death of her mum (her dad died many years earlier), she received a letter from an adoption society informing her that someone from her family wanted to make contact.
The upshot of this is that contact was made and the reunion was successful. My mum is now happily reunited with her siblings and her mother. Her dad died a long time ago so she didn't meet him.
What my mum would say is this (I have discussed this with her) -
If possible, coordinate the meeting through a professional whose expertise is in reuniting birth families.
Think carefully about what you want from the meeting - do you want to ask them questions or do you just want to see how things go during the conversation? Where would you meet? How would you feel if the meeting did not go well?
Obviously, your situation is different to mum's - you spent 13 years with her and obviously there was trauma of some sort that led to you being removed. You mention that you have unresolved issues. I would recommend talking through these with a professional prior to meeting, tbh, as it may help you approach them with your birth mother when/if you meet her.
Good luck.