He Absconded From Prison

My boyfriend is back in custody now but he absconded from prison a few months ago. It was the last straw for me because he had been on a rehabilitation wing and was doing well. As soon as he got to the CAT D prison, he started smoking weed and got in with a bunch of nobs and screwed it all up by doing a runner. I had stood by him for two years visiting him and sending him money so that he could survive and treat himself to some chocolate from the canteen, and he does this to me. He is back in a local CAT B prison and in my opinion he is back to square one. He said me and his son were the most important thing in his life and he does this. I feel like an idiot for trusting him and a letter is ready for him, ready to be posted. I know we will have to stay in touch because we have a son together. it is just one big mess and I know it is my decision on what to do. I just wanted to let off some steam and tell someone.