Hi PureGrace,
Have courage!
Some of the other posters have advised you to talk to your priest, and that is really the best advice. I don’t think anyone here can really give you a definitive answer, because none of us know all the surrounding circumstances.
Personally, with the little I know, I would think that you merely made an ambiguous promise, perhaps something more of an aspiration, and probably one that wouldn’t be considered binding on you.
But even if it rose to the level of a vow (and in your case it would be what would be termed as a “simple” as opposed to a “solemn” vow) then there is also good reason to think it would not be binding.
Why?
Because for a vow to be valid it needs to be given after full deliberation. There is certainly some question as to whether or not you were capable of the deliberation necessary at the age of 16.
Also, for a vow to be valid, you need to have been free from any error which may have affected the reason for making the vow. For instance, if you were in fact in error 2 and half years ago about what kissing entails, or leads to, or the extent of the good which you would be giving up then it can be convincingly argued that your lack of knowledge renders the vow void.
And, even if it was a valid vow (which again, I think unlikely) it still could be dispensed with. There is even a canon law on this topic:
So, it looks like under canon law (although I am not a canon lawyer) your vow (if it was indeed a valid vow) would have been a private, simple vow. And those kinds of vows can be dispensed with by your parish priest (who has been given the charge to care for your soul).
In summary:
- Have courage!
- It can be argued it wasn’t a vow, and therefore not binding as such.
- If it was a vow, it can be argued that it did not fulfill the conditions of a valid vow, namely full deliberation.
- Even if a vow, with full deliberation, it can be argued that it was not free from error, and thereby nullifying it.
- Even if a vow, with full deliberation, and otherwise valid, it could only be a private simple vow, which can be dispensed from by your parish priest.
I offer these comments to you in the hope that it will at least alleviate any fear or despair that you have. They are purely speculative on my part since I don’t have the training or education to really address this topic, nor the knowedge of your particular situation. So take it for what its worth: the 2 cents of random stranger.
But there is someone who does have the training and education to deal with it: your parish priest!

Call him and make an appointment.
God bless,
VC