The 5 stages of grief are necessary to complete before a survivor learns how to manage it and can thus be considered recovered. That is why the first year or two of grief is the most crucial. When a W begins dating while he is still walking the stages of grief (referred to as an "early grief" widower), the temporary feeling of euphoria that comes with new love takes his mind off the hard work grief entails and delays the necessary work required for healing. But grief is like an insolent child - it WILL have its way, bar nothing. Thus, the giddy emotions of new love eventually collide with the insolence of grief when grief plays "catch up" and forces the survivor to get back on the road to recovery. This is when a W takes two steps forward, one step back, limping along his grief journey and confusing the new love of his life as he attempts to complete his grief work while also trying to balance that with new love....a verrrrry difficult and confusing thing for any survivor, and equally as confusing to his new love (you).
When unresolved/delayed grief collides with new love, the W can suddenly turn into someone you don't recognize. His moods change, and he often breaks off the relationship without warning and without explanation. During this time, Ws often battle guilt, depression, and anger all at once. He feels guilty for being alive while his LW is dead. That guilt also includes feeling as if he is betraying his LW by loving again. Oddly enough, though he wants his family/friends to accept the GOW, he wonders why they have "forgotten" LW by doing so! He wonders if he will ever "get over" his depression, which makes him sink deeper into it. He no longer feels worthy of the wonderful love the GOW brings, so he begins to withdraw from her. He is looking for someone to blame for his overwhelming feelings of grief...and sadly, it is the GOW who takes the brunt of it.
The good news is that these episodes of "fits and starts" in early grief widowers are usually temporary...but can vary in length. Every W handles grief in his own way and in his own time, and certain W behaviours are normal and common to each stage of grief. Thus, there IS a light at the end of this tunnel, but it could be a looong time before you see it. It should reassure you that the emotions W is experiencing are very common...and quite normal....for most early grief Ws.
If you believe your W did not properly grieve before he met you, and is only recently attempting to get back on track with his grief, try to be patient. Though these episodes apepar to come out of nowhere, there are usually signs: Holidays and death anniversaries are common grief triggers. The magnitude of what he is feeling is just as confounding to him as it is to you.
The best thing you and W can do from this point forward is to really learn how to communicate effectively...and often. Although I caution GOWs NOT to play the grief counsellor, there are things you CAN do to bring grief to the surface. It is healthy for a W to walk every grief stage completely, so the last thing you want to do is to stand between he and his grief work. It is beneficial and cathartic for W to be able to talk about his feelings. If this is not something you think you can handle - and it would be OK if you didn't - then I recommend urging W to attend Bereavement Recovery classes, or seek counselling wit a qualified grief therapist. These are wonderful people who recognize what W is experiencing and can give him the tools for recovery.
Meantime, try not to take his behaviour personally. I know this sounds odd since you probably feel like the target of his angst, but please understand that a lot of his feelings are subconscious in nature (he can't help it) and perfectly normal for every W. There are many books on grief that you may want to read, as recognizing the stages will put your mind at ease quite a bit. Just remember that this is part & parcel of Loving A Widower….