I’m so glad you wrote. You — and your children and your fiance — are missing out on some of the best years of your life. I can’t make a diagnosis on the basis of a letter, but I can tell you that what you are reporting is consistent with a social anxiety disorder.
You really aren’t stuck with feeling this way. Please contact a mental health professional and make an appointment. With a combination of some medication and some good talk therapy, you can reclaim your best self. You all deserve that.
I wish you well.