1 Confused

My mate recently disclosed to me that he has harbored doubts about the relationship for the past year. Until today I presumed we had a solid relationship much like any other functional relationship (no cheating, abuse, etc). However, he is torn between experiencing a single lifestyle (I assume due in part to his new male friendships) and investing in the relationship long-term. This is our first and only long-term relationship and I am fairly certain that I want to be committed to him. So how can you not be certain after eight years? Has he loved me at all? I also suspect that he may not be happy with himself as he turned 29 two weeks ago and in reflecting on his life, he expressed to me that he has regrets on not accomplishing various things earlier on in his life. I certainly understand how he feels but it is very possible to have a relationship and experience personal growth. Or is it?

I have been in a long-term relationship for 8 years however, engaged for 3. The relationship for both of us is our first and only long-term relationship. Recently he has stated to me that he is not happy with his life as has not experienced all there is to in order to be certain that a committed relationship is what he truly desires. Moreover, for half our relationship he has harbored this doubt but chose to act only to make me content. How can I be certain about our relationship and he is not? Is this common in long-term relationships? How do you overcome such doubt? We currenlty share an apartment together in which we have minimum communication with one another. And this is in part due to his drastic change in character. In the past and now he has not truly communicated with me in the sense that I can be connected to him. This may be the result of me not emphasing this enough to him. I feel as though this is an opportunity for him to work on his ablity to communicate with me in that he can share his emotions good or bad with me. How can I convience him of this? In conclusion, what will not break us with make us stronger. And I want so despartely for him to know that I am not only a good woman but a good person. And if he is willing to discover work on some of his own issues that I will be supportive of that rather than pushing me away completely. Is this relationship worth saving?