Lady's, I need advice about my boyfriend!

Alisa • Happy girl!
Girls, I need advice! We are familiar with my boyfriend over a year. Now he lives in another city because of his work. For the first six months of dating he always showed to my attention, we had excellent warm relations. I am sure that he loves me. And he spoke and said to me about it all the time. He supported me if there were difficulties in my life. But then he disappeared without reason, he didn't answer the phone and didn't call me. His friend with whom I associate told me that he had problems at work. And then my Bf told me the same things and told that all the same good between us. Then I haven't talked to him for almost 5 months. A week ago he found me, we talked last week and now it is again silent. I don't know what to think. What do you think,   can be a reason of this working moments ??? I want to trust him, I love him, but I don't know how he can disappear for such a long time and not interested how I am ?what do you think, should I dumped him, because he is a liar, or wait until he will solve the problem at work and  It is normal situation?