this really comes down to priorities - if you want to make your own mark in life - your own money - then someone else giving you restrictions is wrong. If the two of you were about to get married then I would suggest having a discussion and make sure the boundaries are laid out - and make sure there is openness.
Outside of that - dont count on any relationship as being forever - who's to say that in a year your not with them and in the meantime you have screwed up your chances to really make some serious cash?
My wife is similar to you - she has her website design company and just recently started her own website -
http://www.justsokinky.com - it was something she wanted to do and even though I had some reservations I had to allow her to find her own path.