I don't know where this is coming from, but as soon as I start to develop feelings for someone I start to be an anxious mess. I've generally been a quite successful and content person, with lots of friends and being good socially.
In late february of this year tho I started to show symptoms of anxiety, which thanks to my doctor I got under control. But I used to see a girl at this time (F24) and that relationship made me feel incredibly insecure and in the end it failed, due to us having different opinions on how often we want to see each other.
Fast forward a few months, I met this new woman (F26) and we got of great from the start. She always wanted to see me or do stuff with me, at first I was even overwhelmed and needed space for myself. But after a few weeks I really fell in love with her and ever since I have this nagging feeling she might not like me enough and I am too much/clingy. 
I talked to her about it and she said, that it is absolutely not the case and told me she would say so if it were. Heck last week she even went on a 3 hour drive to meet my parents, so obviously everything is fine. But still my past experiences make it hard for me to just trust in it. So now that she has to study a lot and we don't see each other at work anymore, I start to worry when she is not texting etc. When we are together everything is fine, but what I noticed is, I am very articulate with my feelings, like saying "I am very happy right now". She almost never says those things and once when I asked if she is she said "well obviously I am, or I would not be here with you". Which made me feel like an idiot in return.
I am afraid of opening up all of this to her, since I don't want her to feel responsible for my happiness or mental health or anything, but I sometimes just feel like I need this verbal reassurance. Which then makes me feel like an idiot again. I'd really appreciate some advice or just some uplifting words.


Edit: She just texted me "I'd really like to be with you right now and take a nap". Those little things make me so happy, am I supposed to tell her or would this make her feel forced to text those things in the future?


TLDR: As soon as I really like someone I become an overthinking, overanalyzing, anxious mess, how can I overcome this cycle?