Sorry to hear this OP. My partner of many years did this to me. Also only sent me a text message to tell me. Unlike your situation we had been very happy (as far as I knew!) and actually planning our wedding excitedly, so it was a big shock and I wanted to come in here and tell you I know how it feels for someone to behave so appalingly.
I think the very important message here is this:
There are, say for example, steps to divorce or separation from a serious relationsionship or marriage where you share a home and family.
The first of those might be notifying your partner you are unhappy
Second might be to think of solutions
Third might be to work at it a bit
Fourth might be to seek outside help
Fifth might be to discuss mutually that there is no hope
Sixth might be to spend some time back and forth
Seventh might be to have "the talk" when one or both or you decided it;s time to give up
Eigth might be to decide how best to do that, work out practicalities and the kids
Ningth might be to bite the bullet and separate
Tenth might be to start selling the house / splitting assets and sorting the nitty gritty
Eleventh might be getting to the point where your lives are now separate and you are no longer an "us".
In a "normal" divorce most of these steps have generally taken many, many months if not years to get to and there is time for both parties to adjust. Even if you don't want the divorce..at least you KNOW..at least you get the stages and at least your partner acts like the marriage has some value.
In my case my partner skipped all 12 steps and went right for the finish line. I literally had no clue he was unhappy - he said the opposite. In your case he went through the first one and maybe the second and skipped all the rest.
So what i am saying is that you've been deprived of due process. It's therefore a shock. A trauma. I KNOW how you feel..I have been there with DS asking me where Daddy was and me not knowing what the fuck to say because I thought it was a joke.
What is really key here is to understand that regardless of motive, of whether he has someone else, of whether he comes back or not....you have to understand how monumentally cowardly, selfish and fucked in the head it is to skip those steps. Chances are he has probably been through 5 or 6 of them and his own and has given himself a chance to take it in but not you.
Translate that to the very real reality that your DH, no matter how great he once was, might well have ceased to give a shit about you. I can't tell you if he will come back or why he has done this but I can tell you it's abnormal and indicative that he has decided to take a rout where your self protection will be paramount.
Chances are he will now turn on you. Become financially difficult. Devalue you to make himself appear the victim. Probably lie to family and friends because he is a coward and will be scared of being thought badly of. Probably use DD against you. Try and make you feel crazy.
these are are the things the man I loved most in the world did to me, and I sit here years later still unable to believe WTAF happenned or how or why he did that to me.
The fact was, the moment he missed those 12 steps he showed me who he was and how he was going to handle things when the going got tough.
I took him back three times, and my the end of it was suferring from PTSD. I can't stress eough what a wonderful partner / father he was before this.
Yes, some men do come back and people reconcile. HE might only be gone 2 - 3 weeks. Whatever the case is though....you need to do what I failed to do and realise the behavior is a symptom of something else and get into a position where you look after yourself and at least temporarily protect yourself from him.
I have another thread on here tonight aout difficulties with my new partner, which all stemmed from the living hell my "sweet" and "loving" xDP put me through when he randomly decided to fuck off. It's hell on earth...please stay here and talk to people because situation like this make you forget what is normal and what is not.