Is it normal to feel depressed without motivation?

I have no motivation in me. No matter freaken what, I just don't care enough about anything to make me want to pursue it. The only time I felt really motivated like I have to get my sh*t together and I can a better person was with my ex. He's a very ambitious and smart guy, I was just madly in love with how confident he was and it made me want to be a better person for him. Now that I don't have him, I'm back to not caring about anything. Unless I start thinking of him, I can't seem to find the desire to do something. The thing also is I randomly get motivated almost like a bipolar thing. I am also goal oriented, I know what I want to do but I haven't had that much motivation to actually go out there and pursue it. Again, whenever my ex would mention something about my career or interests, it would get me going. But now without him, yeah I have myself to look to but I have no motivation most of the time. It's so hard to find it. You need the passion and I happen to be pretty careless and easygoing so it doesn't help me pursue my goals. So as I grow up, Im starting to get depressed about it. I think it's a part of growing up like you have to have something to fulfill you that will keep you going and I do not have that. So it's this emptiness I feel that is making me feel down almost every single minute now.