Struggling with being needy in an ill defined relationship

I (19M) am in a rather complicated 'situationship' with a woman (22f) and am somewhat struggling with how I should be feeling/behaving. We have been facetiming regularly over the past couple of months and we both have expressed a want to possibly move to a more serious relationship when we are able to see each other again in a few months time (she is in the states and I'm in the UK before she moves back here). When we hung out in person it was very intense but we simply haven't spent enough time together in person to start a proper relationship and we are both aware of that, and it would be unfair to commit to anything really serious at this time. However we are definitely more than 'just friends' at this point.

However, I feel like recently things simply haven't been that great between us. She has been slightly distant recently and any kind of sexting or flirty contact we once had has stopped. Things used to be really great and we usually have great communication about how we feel and if something is upsetting one person. When I gently asked her if things were going okay between us, she insisted that she had no problems at all, but I definitely feel as if things have changed between us .

I have a horrible habit of overthinking stuff wildly and am aware that she doesn't owe me anything as she isnt my girlfriend, but frankly this change is making me feel unhappy. Of course long distance combined with us both being locked down with our families is not an easy situation but I feel like I'm making more of an effort for things to work out, and I dont want to feel like I'm somehow forcing her into anything if she isnt keen. She told me recently that she struggles with showing affection, but does still feel a spark but I still feel insecure about the situation. I have tried to express some of how I feel to her but am worried that I'm coming across as needy and insecure which of course is unattractive. Recently I have stepped back from the situation a bit (less intense facetimes and irregular texting) but I still want things to work out until we can actually see each other in person again in a more normal situation that isnt just through a computer screen.

Any advice on how I can relax a bit and maybe not feel so needy or steps forward?