Hello Shaz. Welcome!
I'm sorry your relationship is being affected by your partner's moods. Is he getting other support apart from the love and patience that you give him? My partner was rather the same when we started out 18 years ago. It took a lot of acceptance on my part that he had been hurt before and his default position was fear of being hurt again. It took him a while to understand that the worst was not going to happen in our relationship. I don't know if there is any easy way through this. If he gets some help, that takes some pressure off you at least. Does he feel optimistic about the relationship when he is in a more relaxed and happy mood?
You are very wise to seek some support (here) for yourself. I think that one of the important things is that you look after your own wellbeing so that you can remain strong.
Would he consider some counselling as a couple so that the two of you can discuss his fears? It can be useful to do this in a neutral space. While some of this depends upon the likelihood and seriousness of what he fears will happen, the fears themselves may be an even greater impact on your relationship. It's important that you reached out. Having rambled a bit, I would suggest that some of what happens will depend upon him and what he is willing to do. The thing that I realised with my partner was that it was important for me to have clear boundaries about what was my responsibility. I think that helped me to work through those early years.
