I do not think Samson Is necessarily a monster. I think the shock of the news that Amelia was pregnant, and the perceived change in his life was just too much for him to come to terms with. One minute he was making plans for his future after getting good exam results, then suddenly he feels all this is being taken away from him, at the prospect of being a teenage dad. Hopefully when he has time to reflect, he will adopt a more reasonable attitude.
I think children are forced to grow up too quickly nowadays, I think the change from playing children's games to sexual awakening seems to happen overnight. And now with pressures generated on the internet, influencers, marketing and advertizing targetting teens, is very difficult for them to develop at their own pace. Both Noah and Samson have found themselves in situations that they are not mature enough to handle. Noah's concern for Amelia has shown him not to be the monster, Kerry and Amy paint him to be. Without their pressure I wonder if Chloe would have went to the police, and Noah might have escaped a criminal record. Now we wait to see if Samson suffers the same fate, as Amelia would have been 15 at the time.