Acts 1:21 Wherefore of these men which have companied with us all the time that the Lord Jesus went in and out among us, 22 beginning from the baptism of John, unto that same day that he was taken up from us, must one be ordained to be a witness with us of his resurrection.
23 And they appointed two, Joseph called Barsabas, who was surnamed Justus, and Matthias. 24 And they prayed, and said, Thou, Lord, which knowest the hearts of all men, shew whether of these two thou hast chosen, 25 that he may take part of this ministry and apostleship, from which Judas by transgression fell, that he might go to his own place. 26 And they gave forth their lots; and the lot fell upon Matthias; and he was numbered with the eleven apostles.
I don't know how this was done, or if it is Biblical to do it today. It was, however, done by a group of people rather than one individual and the decision was something that affected the whole group rather than just one person. I haven't studied this matter, but offhand, I would say that it wouldn't be the best method for making decisions for your own life. I could be wrong about that, but you should pray that the Holy Spirit to guide you. It might also be a good idea to talk to other Christians you can trust about the situation.