I'm right-handed and then you should think that the right hand is dominant, but it's still the index finger on the left hand that's strongest when it comes to magic and that kind of thing. When I use the wand, I know more about the energy in the left hand than in the right hand. So that it's the hand you're writing with, which is the most dominant, is just a myth you should think.
I think a scene from the old (old, old, old) movie Willow puts it well.
Willow took part in a trial for magical apprenticeship at the beginning of the movie and failed. The applicant had to answer one question; "The power to control the magic of the universe lies in which finger?" Willow had hesitated, then selected one of the five fingers held out by the elder. It was wrong, and he was rejected.
A little later, after being faced with his hero's journey and in the midst of preparing to leave, the same elder took Willow aside. He asked Willow why it was that he hesitated, and asked what the original answer was going to be. After some cajoling, Willow finally responded that the answer he wanted to give first was "My own."
Naturally that was the correct answer.
Wisdom can be found in many places. I was using the scene as a means of explaining your situation. Apparently the effort failed so I apologise.
The point was that each person operates differently. While it is indeed most common for a person's dominant hand to be the most geared towards moving energy outward, it isn't always the case.
In truth both hands have the ability to take in and also project out energy. But people work through association. The fominant hand is what one uses to manipulate things. reaching, grabbing, turning, cutting, throwing, and other 'active' behaviors. So it is natural habit for the mind to associate similar 'active' uses of energy. Such as projecting, shaping, and attacking.
And likewise, the sub-dominant hand is more often utilised for coltrolling things. Bracing, steadying, holding, catching, and blocking. Likewise this reflects on the mind in association with drawing energy, pushing or pulling, holding, and blocking energy.
However part of that is also learning, practice, and habit. Right-handed boxers can end up favoring south-paw fighting. Right-handed fencers can end up gavoring the sword in the left hand. Heck, right-handed people can favor holding a knife and fork backwards. Because that was how they first learned those activities, that is how the associations between active and passive action formed for them.
So, long story short, while yes it is largely true that the dominant hand will be the 'active' hand in energy-working it isn't always the case. But it isn't anything to fret over because what works for others isn't always going to matter. What -does- matter is what works for you. Magic is less about universal 'facts' and more about Self discovery.
So don't be overly worried about the fingers of others, because your power comes from your own hand. Not someone elses.
Only you know what you feel. I think its interesting what you experienced. The myth about dominant hand and magic probably isn't exact since there seems to be a spectrum in everything. I use both hands in practice for different things, but more often than not I use my left hand. In daily life I basically quit using my left hand. I know that some energies or information I can more easily pick up and understand when held or felt in different hands. Its helpful during daily life. Sensations in either hand tells me different things depending on the situation. I am a lefty, so when my left hand gives sensations it is usually positive and personally relates to me and my emotions. When its my right hand its more real world daily life stuff, or something negative, or that I should hold off on my plans.