Tyrese has offered an explanation for his erratic behavior in recent weeks -- he says a new medication is to blame.
Tyrese claims his online meltdown a couple weeks ago was caused by the drug Rexulti, used to treat depression, having an adverse effect on him ... but he's off it now and getting back to normal.
The actor says the meds made him do things over the past 2 months that effected a lot of people and he wants them to know he's sorry.
As we've reported ... Tyrese is in a bitter court battle with his ex, Norma Gibson, and he says doctors recommended the meds to him to handle the stress.
Friends of his like Will Smith and Jada Pinkett expressed concern that Tyrese was having some sort of mental breakdown, but according to him ... he's on the mend now.