I need help with my relationship

I have been in a long distance relationship for nearly a year now. I have been in love with my partner for a very long time and am very connected with them. However, I have dealt with lots of mental health issues because of the pandemic and was recently extremely stressed. This stress caused me to have a burnout where I cried for hours with no reason . My partner has always been there for me and our relationship was amazing when this happened, yet after my burnout I feel nothing towards them. I have been hanging out less but out of nowhere i suddenly can't see our future. I think that I may have lost feeling yet when I think of leaving them I become extremely sad and begin to cry. I am so confused because I don't understand how I get so sad and can't imagine my life without them when I feel nothing currently. Have i really lost feelings or is my mental health causing these issues?