Panic at being incapable of being in a relationship

I've been dating a guy for a little over 3 months now. Recently we were cuddling and he said he wanted to talk to me about something.

Him: "I don't want to be a jerk, but how do you feel about us?"
Me: "I feel good... I really like you."
Him: "I really like you too, but I wanted to talk to you because I haven't been feeling an emotional connection to you. I haven't felt a spark yet."
Me: (heart sinks) "Oh..."
Him: "I don't feel like you're being yourself around me, and I don't know how to joke around with you because I'm not sure how you'll react to certain things yet. I really like you and I'm just saying this because I want you to let your guard down."

We talked about how I said to him recently that it takes me a long time to warm up to people and be comfortable with them (I'm very shy/reserved). A week or so ago I had mentioned that I feel like I have a sense of who he is, but I'm not sure if he yet feels like he knows who I am. I said that I wanted to try opening up to him more. I think I craved more emotional connection too. I do find myself getting nervous around him and have a hard time being myself, and I had noticed that we don't joke around with each other enough. But knowing me, I know that it takes time.

He is actually reserved too, and he said that his mom doesn't see us together because she pictures him with a more outgoing person. Maybe we aren't a good combination if both of us struggles in this area. Though I really like him for so many reasons. I felt hurt as he was talking, especially because I've always felt like I like him more than he likes me (for several small reasons, like I am always initiating the dates and he doesn't often say things like "I miss you" unless I do first, etc). He said there is no problem with our physical/sexual connection, but the emotional/romantic is missing. We've been opening up recently and having deep conversations, so I was hurt that he felt that way. I thought it had been going well recently.

I think I've forever felt worried that I am incapable of having a relationship. That I'm too shy and will never be able to be myself around someone. It's hard enough with my friends, and though there's the argument "when the right person comes along, you will be comfortable being yourself," I'm not so sure in my case. So his words really knocked some panic into me. He did say many times that he really likes me, and said he can be patient and see how it goes for another few months, but that he wanted me to know this because he wants a whole connection.

How can I relax more and be myself? Do you think it's possible that I'm incapable of doing so? How long does it take to get more comfortable with someone?

This man is very mature and honest. That by itself should make it easier for you to be more open with him. How long it takes for a person to get more comfortable with another person depends on each person. This man is at least comfortable enough with you to have this conversation.

Whether you are capable of doing so, depends on you. Is there anything about this particular man that makes you uncomfortable? Does he remind you in any way of any one else in your life that you weren't comfortable with? If so, you discomfort with him may likely be rooted in the past and not anything to do with him.

Usually, when a person has difficulty opening up to people, it's because there is something about themselves that they on some level don't want anyone to know. They fear that if they let someone really know them, that person won't like them or judge them. Do you do a lot of internal negative thinking about yourself? You're not good enough, pretty enough, smart enough? If you do, you need to spend some time focusing on the positive things about yourself and addressing those things you don't like one at a time. Choose something simple, like, if you don't like your hairstyle, try a new one. Do things that boost your confidence and esteem. And, in the meantime, choose one thing that he doesn't know about you and tell him about it. Do it in bits and don't choose anything you feel is "really big". Do it gradually.

Be yourself and try to go with the flow. I think if you two try to define it too much then it may be over analyzing and not helpful.

How about watching a movie together and hold hands? The intimacy is there and you can quietly be together.