If you don’t feel in love within 4-5 months, is it a sign to let go?

I (29) was in a long-distance 5-month relationship (30), although we saw other enough based on the duration of the relationship, in my opinion. We would usually spend 2-3 days in a row together per week or every two weeks basically since the beginning, sometimes even 5 days in a row and we also spent two weeks in a row together with two days separately in between. Unfortunately, we broke up today…

We haven’t seen each other for almost a month due to work related reasons as December was very busy. We had plans to see each other tomorrow, but today I expressed to him that I didn’t feel enough enthusiasm from him to see each other, which turned into a long conversation and him admitting that it was getting hard for him to do the long distance, that he felt as if he didn’t have a partner when we were not together. I felt blindsided, because he never expressed such feelings to me before. He did say that he wanted a relationship where he would spend all the time together with his partner before our first date, but I thought that would come with time and had no idea he already wanted that and that he felt lonely.

A month ago I admitted my feelings to him, told him I loved him, he didn’t say the same in return, but I thought it was okay, because everyone moves at a different speed. He told me today that he got scared when I said I loved him, because he didn’t feel the same way about me. He said that he thinks I am cute and physically very attractive to him and he likes me and enjoyed spending time with me and he thought his feelings would grow, but he didn’t feel more than a crush/fascination yet and didn’t know if he would develop stronger feelings and didn’t want to lead me on. He only was in love once and his ex moved in with him within the first 2 weeks of getting acquainted…

I told him that I didn’t know that he felt that way about the distance and suggested to spend more time together to see if the feelings would grow as we were dating for only 5 months and were officially a couple for only 3.5 months. But as I understood he doesn’t know if his feelings will grow and doesn’t want to “play with my feelings”, even though I myself suggested to keep seeing each other and spend more time together.

Are 3-5 months really enough to decide that you will not fall in love, especially in a long-distance relationship and to give up? Did he lead me on? I feel blindsided and hurt that he kept silent how he felt about me for a whole month and didn’t tell me that he felt lonely when not together. After I admitted my feelings we kept talking as if nothing changed, I didn’t feel him distancing or getting colder, he still kept sending heart emojis and stuff.

tl;dr Boyfriend broke up with me due to being afraid he would not develop stronger feelings for me and refused to see each other more to develop them, should I try talking to him or just let him go because 3-5 months is plenty of time to know if you love somebody?