Boykin -- a former TCU superstar -- was accused of choking and breaking the jaw of his girlfriend, Shabrika Bailey, during a fight back in 2018.

Trevone was facing DECADES of prison time after he was hit with two felony charges in the case ... and to make matters worse for the 26-year-old, he was also arrested again months later.

In that case, Boykin was accused of stealing money from fans in an elaborate memorabilia scheme ... and was hit with two additional theft charges.

But, the Tarrant County District Attorney's Office officials tell us Boykin reached a plea agreement Wednesday to close out both cases.

According to a DA spokesperson, Boykin pled guilty to felony aggravated assault and felony tampering with a witness ... and he also pled guilty to two misdemeanor charges of theft.

We're told Boykin was sentenced to 3 years in prison for the felonies and 180 days for the misdemeanors ... but the sentences are set to run concurrently.

"Mr. Boykin has failed to take responsibility for any of his assaultive and criminal behavior up until this point," prosecutor Allenna Bangs said in a statement.

"The victim in this case sustained a long-standing relationship of abuse by Mr. Boykin and, along with our office, feels his prison sentence is vindication for what she endured and the consequences he was able to avoid in the past because of his ability on the football field.”

We spoke with one of Boykin's attorneys in the case, Steven G. Gebhardt, who said of Trevone's feelings on the agreement, "I think he's glad to just have it over."

Gebhardt added Boykin is now looking to continue his football career once he's released from prison ... telling us, "We believe that door has not closed."

Boykin had huge potential during his time at TCU -- he was once considered a big-time NFL prospect -- but he couldn't stay out of trouble, most notably getting arrested for fighting an officer just days before TCU's 2015 Alamo Bowl game.