Feels Like I Am Eating Back My Words

I was sooooo certained yesterday...
Yet once again I am confused and indecisive.
I discussed with my dad about my determination of going back to college to get a degree.
He adviced that the choice is up to mine.
However, he told me this one thing which makes me hold back my decision to go back to college.
You see, I will get my degree if I successfully completed the 3 years course.
However I am working now and in 3 years time I can easily get a promotion (that's what my dad said) for the job I am currently working at.
Now the question is, 3 years to get a degree and work as a freshie for chosen course or 3 years to work without a degree & wait for possible promotion?
Advice people?
But I do feel like going back to college...
Gosh...
Am I thinking too much or what????!!!