Hi SamiJ and welcome to SR,
I have known my AH for 30 yrs, married for 22 yrs and have been where you sound to be plenty of times, upset, hurt and wondering what I have done wrong to deserve not being spoken to. In the end I would stop speaking to my AH and this would lead to 'mutual shutdown'. This could drag on for weeks until I broke the ice and more often or not apologized! Its a roller coaster ride of ups and downs or a merry go round of repeating yourself or thinking 'here we go again' - it eventually makes you feel sick. By the way 'Merry-Go-Round Called Denial' is a leaflet produced by Al-anon and is one of my personal favourites. Its up the top somewhere - do a google for it, its worth a read.
Not being spoken to can be a form of abuse, depending on how it is being administered and that in itself is something to think about.
What exactly are you trying to talk to him about? Why has he stopped talking to you? It sounds like something is simmering away in your relationship and is going to reach boiling point soon but not too sure from your thread exactly what is happening. Perhaps you can expand?
Your boyfriend sounds irrational and alcohol will do that to you. It is very hard to try to rationalize an irrational person, so I am not even going to go there.
You cant do anything at all about him, we talk a lot about the 3 c's - you didnt cause it, cant control it and cant cure it. The good news is though that you can do something for yourself that will help a lot. I am going to suggest that you try Al-anon, there you will find lots of direct support from people who you will relate to. That in itself is a huge relief. Keep coming to SR for support too and read, read, read. You will be doing something huge, indirectly for your 6 yr old son too as he deserves at least one health, happy, content parent in his life and that person by the sounds of it, has to be you.