There is no statute of limitations and there is likely a bench warrant for your arrest. You face an enhanced sentence.
The above answer, and any follow up comments or emails is for informational purposes only and not meant as legal advice.
There is no way for you to 'wait this one out'. The matter is still active, and a warrant issued for your non-appearance can come back to bite you anytime. For example, a routine traffic stop, a trip through an airport as you're getting ready for a family vacation, etc.
Not only is there no statute of limitation, the judge is no longer obligated to give you the promised sentence. They can give you the maximum sentence to the top charge you pleaded guilty to and if you are brought back against your will, I wouldn't be surprised to see that happen. In addition, you potentially face additional indictment on Bail Jumping charges (even if bail was zero) and up to 4 years jail its sentence could be ran consecutive to your gun charge sentence.
215.56 Bail jumping in the second degree.
A person is guilty of bail jumping in the second degree when by court
order he has been released from custody or allowed to remain at liberty,
either upon bail or upon his own recognizance, upon condition that he
will subsequently appear personally in connection with a charge against
him of committing a felony, and when he does not appear personally on
the required date or voluntarily within thirty days thereafter.
Bail jumping in the second degree is a class E felony.
I am a former Brooklyn Criminal Court Deputy Bureau Chief with over 17 years experience specializing in handling criminal cases. All answers are for information purposes only. Answering this question or any future questions does not form any attorney-client relationship. Be mindful, that answers are limited by the limited facts presented by the questioner and are not meant to take the place of competent legal advice by an attorney fully informed of all the facts surrounding your case. Also, be aware that nothing posted in a public forum such as this can be deemed confidential or privileged communication.