Some time ago, I was. In a sense, it still lingers in the back of my mind. However, remember and get to grips with what a vocation really is. I mean, what it really, really is. How to do this is through prayer first and foremost, and then through reading and understanding. For me personally, reading the Gospels made me understand my vocation. Remember that we all have a vocation - married, single life, priesthood, religious life. The joy is finding out what God wants from you. This is what discernment is about. A vocation is “doing God’s will”. In an etymological sense, it is the “calling” of God.
What I am trying to say is this: I sincerely believe that if you are afraid, you must re-asses and ponder over your vocation and discernment. Christ brings joy, and peace. Which is not to say you won’t be nervous, apprehensive or slightly scared. But there exists an inner joy and peace which is what a vocation is actually bringing about: that state of the soul which is the never-ending “Yes!” to Jesus Christ. Do not be afraid. When you are discerning, I mean, really discerning, and when you understand a vocation, you understand that Christ is calling us and all we need to do is say yes and He will guide us. Not passively, mind you. He guides, and we, in joy and obediance, follow Him and do His will. So there isn’t discomfort or fear. There is only Christ. Complete and utter commitment to Christ in whatever He wants.
With this in mind…
A) Not being accepted
You might be, you might not be. Not the end of the world, but only the beginning if you are truly discerning God’s will. For me, I believe I am called to the religious life. If the Transalpine Redemptorists (F.Ss.R) don’t accept me, I will accept this perhaps not joyfully but gladly knowing that Christ wants me elsewhere where I can do better work for him.
B) Telling the quite bitter-towards-catholicism parents
I can relate to this. Trust your parents is my advice. Trust them to love you enough. And furthermore, pray to the Holy Family. Things will be fine.
C) Going through years of the seminary then being told ‘You’re not called’.
Praise God! Because if this happens, you will know that God is calling you elsewhere and you have an opportunity to serve Christ in the way that He truly wants you to serve Him.