Not what I expected for our first Christmas together as a couple

Christmas Eve dinner was at my parents house, had a lovely dinner, opened presents and visited with my aunt, neighbor and cousin who were also present. SO was feeling low, since this is supposed to be his Christmas to have SD(7). So low that he barely spoke, had sad face all night and cried at the end of the evening. 

We came home that night and I confessed that it hurt my feelings and I felt childish but it did kinda make me feel like he didn't want to be there with us. He apoligized and reassured me that he just wished she was there too.

Christmas Day comes and started off lovely we opened gifts, had breakfast...then a dark cloud descended and he basically locked himself up for the rest of the day. Was not allowed to even speak to his daughter on the phone.  

Later he got incredibly angry at me, which I will get into shortly, about something I had said in regards to a phone plan for the kids gizmo watches they got from their BD. He told me he doesn't want to go with us to see my Mom this weekend up north to play in the snow and is seriously questioning our relationship.

I never noticed before this relationship but it has become a huge problem with SO that I am so forgetful.  It always seems to be the tiniest things that he brings up, something said, something done, and I just don't remember it. It is so frustrating to me because in the end its not really even stuff that matters. But it upsets him so much he just berates me for having no memory whatsoever.

My ex asked what he could get for the kids and I told him the gizmo watches would be great so they could play in the neighborhood and we could know where they were and if there were any issues after school picking them up we could call them. Well SO had a major problem with me paying for the monthly service and insisted that I tell my ex RIGHT AWAY that he had to pay the monthly service (even though our money is separate, and I wouldn't be compromised financially if I had to pay $30 a month). So as I am trying to set up the watches yesterday, he demands that I come to the room to talk to him and there continues to rip me a new one for "lying".  

Now I know how lame this sounds and it again is something that drives my SO insane, but I don't remember saying what he said I did. He said that I told him I already told my ex he had to pay the monthly service charge. I didn't remember.  He is now saying he can't trust me, I'm a liar, I can't be honest and he doesn't want to be with someone who lies. 

I suppose its possible I lied and said that i had already told him just to get him off of my back. He becomes relentless when his mind is set on something and in a way I see it as a non-issue who pays the $30 a month. Its such a small amount and the watches themselves, which the ex paid for are about as much as a year of service for both. 

So he yelled at me for lying and said that I lie constantly...and on and on. I feel like its ironic that he feels like I'm the liar when he didn't tell me he was still married until he had been living with me for two months. But it was all her fault because she wouldn't sign the papers.

More and more I just feel like this relationship is just too hard, even though he otherwise has been amazing and a great person to be around.  I don't know whether to suggest counseling or not, to just call it quits now before we're both stuck, or some other third option.