Hee brrokee my trust and i dont knoww how i should be reactingg?

ive been seeing this guy for the past few months, and honestly have strong feelings for him and uptill this week hes treated me well. we only get to see each other on weekends but he told that saturday he would not be able to hang out cuz he ahd to go work .. everything was fine but randomly on sunday when we were supposed to hang out he didnt message me AT ALL .. no goodmorning or anything so i messaged him several times asking what was wrong but no reply .. honestly i was so worried that something happen or that i did somthing wrong... So on monday i come to school and i find out from a friend that he wasnt at work on Saturday but with her boyfriend hanging out, i honestly dont understand whyy he had to lie i wouldnt have cared if he cancelled on me to hang out with a friend but when he found out that i knew about him lying to me he mans up and texts me saying sorrryy that his lifes fked up and that hed explain to me later i did not get mad at him ONCE didnt even yell and i forgave him almost instantly it turned out he was just in a bad mood and didnt wanna talk but he did not admit to lying to me .. all he had to do was text me ONCE saying he cant hang out, i had caneclld my plans for him. honestly i was hurt and everyone is telling me to movee on but i really like him should I give him another chance cuz he said hell never do it again but thats what they all say or should I just dump him . i think its possible that he just doesnt know how to act in a relationship =/ because hes used to jusst having nsa relationships