I need solid, honest, unbiased advice

Hello, I've been with my "husband" for 6 years. In the beginning we dated for 3 months, then I got pregnant unexpectedly at 18 and we stayed together and worked on our relationship because of our son. I put "husband" in parenthesis because in everything we are married except for that ceremony which makes us legally hitched. We've had a rocky relationship. I love him to death but he has a horrible temper where he says the most horrible things that years later has left lasting scars on my heart. In all other ways he's the love of my life. The past few months I've been thinking seriously about bringing up getting legally married. We have always said that we didn't want to just go to the courthouse and do it. That we wanted a nice wedding. It always seems every year I think about it and then something happens between us that makes me think otherwise. Such as a fight where he says unreasonable almost insane things and then is emotionally abusive. But lately we haven't been going on our usual dates. I've noticed he's been talking to a bunch of women on facebook, which back when our relationship was solid earlier this year didn't bother me at all. It's just lately it makes me uncomfortable. I find myself checking his phone and other insecurities plaguing me. He seems so distant. And all I want is to spend quality time with him. In checking his phone I found a message to a woman from his school that he used to be good friends with and even slept with one time.(who happens to be a lesbian now) the message goes along the lines he asks how her gf is she asks how his wife is and he says "well she's still here and life couldn't get better i suppose..." and she says "oh is that right" and he says "prolly not"...I'm just so confused and if you read this I apologize for the rambling and lack of putting this all in a sensible paragraph. But I've been so depressed for the last few days I can't stand it. And I feel like I can't talk to him about it. I need advice. Nothing vindictive. Nothing negative. Solid, honest help.

I think you should just come out and ask him if he wants to get married. That will make you guys a lot more closer. & it's not like you guys are fighting it's just you two are drifting apart