I have a couple of book suggestions for you. The first is the 5 Love Languages. (That's not the exact title but close enough to google.) People express love and receive love for others in very different ways. If partners have very different ways of showing and understanding love, that can cause hurt feelings and feeling lacking or even not loved. The author has proposed that most people fall into one of 5 basic ways of expressing and receiving love. Most people have one or two 'languages' they they are strongest in. If you google five love languages there are several free tests on the Internet you can take to see which love language is most prevalent for you. The book is also easy to buy used or get from a library. So for example, I am highest in 'Quality Time' meaning I will spend time with someone to show love, and it's how I feel most loved when my loved ones spend time doing something with me. My ex's strongest love language is 'Touch' - she needs to touch and be touched to feel loved and valued.
It sounds like you, your husband and your GF have strong feelings for each other. It also reads like you express and receive love differently. The book can help each of you 'translate' your love languages for each other. Sometimes just understanding how each of us feel and show love is incredibly powerful. It won't solve everything but I've found it super useful in all of my close relationships, romantic or otherwise.
Also from reading your post I get the feeling that your GF may be more introverted than you or your husband. You 'read' to me as someone more extroverted as in you get energy from interacting with other people. It's also possible that she is more into introspection and alone time right now as she heals from what sounds like a difficult divorce. But I would bet that she needs more time to herself than you do because introverts are drained by interacting with people, even beloved ones, and need time to recharge. If this is an accurate read, I suggest the 'Power of Introverts' by Susan Cain which is in libraries, Amazon etc. Cain explains clearly why introverts do what they do ad how it is normal and necessary for them. It should be required reading for anyone dealing with an introvert - which is almost everyone.
Two final thoughts. First there is nothing wrong with you and nothing wrong with her. You just experience love differently and you communicate differently. Do your best not to approach this as she is failing you, or doing things wrong. That can be very corrosive. Second, you have the power to decide to take this as an opportunity for some $&@*%# personal growth and learn how to be in a relationship with someone who does not match up with your preferred ways of showing love or communication style or extroversion level. Good luck!