I know how it feels as I have gone through a similar situation as well. Just believe in yourself and move ahead and take your new position. Remember that every company management evaluates a persons ability to perform before making a job offer. Obviously, you working in the same company, your capabilities are noticed. Sadly, when you are being interviewed for a job in a new company, they have only your certifications to look at as a yardstick to gauge your abilities, and in such cases non degree persons suffer even if they are capable and experienced. Call it jealousy or ignorance, but some people with high academic credentials cannot digest the fact that they are being manged by a capable person who is less qualified on paper. That being said, there is no substitute to hard work and dedication.Your gradual ascend is proof enough of your capabilities. Take up your new challenge and Best of Luck!!!