Pushing her away?

I have been with my lady for a few months and she is amazing. She brings out the better in me. She knows what she wants. She is a true sweetheart. If I get home from work late and I haven’t ate she does fuss at me in the phone but ends up ordering me food, since I’m too tired to cook or she is unable to drive to me. She even is meal prepping for me so that I am able to eat better when I get home. I can literally talk to her about any thing with no judgement. I talk to her about my issues with my child mother and at times I’m cursing and yelling. Not at her but at the situation. But she is always there to listen and help me the best way she can to make it ok. Ordering me food and meal prepping for me may seem small to some but she really cares about my well being. She forgave me for DMing women on social media and I know her trust for me is tarnished. But she forgave me, and here I am not being serious when she is being serious. We both are goofballs.
I have noticed now that when she just tries to talk about the relationship I tend to get weird. I start to make little jokes, knowing she is serious. I be knowing she is trying to have a serious conversation but the jokester in me comes out. I can tell in her voice it bothers her and she ends up getting off the phone afterwards. I don’t even know why I do this. I sent her a text late last night thanking her for everything. I was stupid and I sent a text sayin “I love you” and unsent it (on iPhone you can do that now) I did it as a joke but it really bothered her. I didn’t mean any harm. She got upset over it. She says that’s not a word she plays with. Today she told me how it made her feel but I played it off like an idiot, and she got off the phone to go to the gym after that. Now I’m sitting here in my thought feeling like I’m pushing her away with my jokes on serous times. She is a great woman and I don’t want to lose her. I am 37 she is 35.