Two disciplinary tickets adding up to over six months of sanctions is serious, and the concern you feel as a parent is completely understandable. But the harder truth is that this is also a critical moment that could go one of two ways for your son.
At 19, he is at an age where the habits and patterns he establishes now inside will follow him. Inmates who accumulate tickets early tend to accumulate more. Each one goes on their institutional record, affects their classification level, costs them privileges, and makes parole or early release harder to obtain. The first couple of tickets are survivable without long-term damage if the behavior changes. A pattern of tickets is a different story entirely and leads to solitary confinement, higher security housing, and a much harder stretch of time.
The lesson prison is trying to teach with those sanctions is exactly what you already know as his parent. Stay out of other people's business. Do not get drawn into situations that do not belong to you. The company you keep inside matters as much as it does on the street, maybe more.
What he does from this point forward determines which direction this goes. A clean record from here out can eventually offset early disciplinary history. Continued tickets compound the problem in ways that become increasingly difficult to reverse.
If you can get a message to him, keep it simple. Head down, mouth closed, stay away from the people who got him those tickets in the first place. He has too much life ahead of him to spend it in a deeper hole than he is already in.