Anxiety and long-term relationship: need advice!

I (23F) have been in an amazing long term relationship with my BF (24M) for the past 5 years. We did not really have to go through any conflict or fights, our love always seemed to come easy.

However, I have been getting extreme anxiety lately. I have started struggling with this about a month ago, when finishing a very busy project for my uni. I started to get distressed about having too much free time and not having any idea what to do after I graduate, but this anxiety has then moved on to my relationship as well. I have been feeling generally uninterested in everything but this also relates to my boyfriend. I am not feeling the same way towards him and I do not know whether this is because of my mental health or it is simply me falling out of love. I have very mixed feelings in different moments, some days I feel ok and I am able to enjoy time and sex with him, on others I just want to be alone and I want to understand myself on my own. I have moments of extreme anxiety when I can do nothing but cry and feel anxious and lay still on my bed and in those moments I feel scared that my relationship is doomed.

I have tried to tell him I need more alone time and he has proven very understanding. However, I do not know whether I need a break or a breakup to recover and see how I feel without him, because RN I am not being my best self and I am definitely cutting back on attention and care towards him.

Has anyone gone through this? Do you have any advice?

TL;DR: I am getting extreme anxiety and I do not know whether I still love my long-term boyfriend.