Blue-stalling? Confused?

I have been seeing a guy for 5 months now. We are official, he has introduced me to his friends and his family. In the beginning everything was wonderful. He was attentive, wanted to see me all the time and always use to check in by message. Lately he has grown kind of distant.
he messaged me a month back out of the blue to say he needed to bring up with me that he wasn't sure how I felt but he wanted to continue the way things are and progress our relationship naturally, but wasn't ready for anything heavy. I agreed as I had been hurt in the past and didn't know if he assumed I was someone to rush in and want marriage, move in (after about 3 months!?) He said he wanted to talk properly about it but every time I tried to, he avoided it. His excuse and response was he was use to being on his own. We continued seeing each other and things were ok. Bear in mind this message still bugged me. His messages became sporadic. Sometimes he would message me, others I had to do the chasing. He started to not suggest plans for us to do anything together, but if I asked he was always happy to do something.
He is a busy man with his job and he is studying too. It has also been a busy time lately with parties and such being Christmas.
Sadly a few days ago my dog died. He isn't a pet person so his sympathy was as much as he could give me in a text. He saw me the day after as I wanted to take my mind off things. That day was ok, but what got to me was he never suggested any plans for seeing each other over Christmas. All he spoke about was meeting his friends. He now only seems to reply when I message and that is that. I feel like a complete fool and I am doing my own head in thinking is it me? I haven't had a relationship in 6 years so I don't know what to expect now in an adult relationship. Is this normal? Am I going mad? I don't know if I should confront him or how I should do it, I feel a bit too fragile for that at the moment.