Anxious and unfulfilled

Before anything,I would just want you to know how grateful I would be if you read all of this because it really is a big thing to me, thank you in advance! Hello, a few weeks ago I had a problem with my breakup and I though that the lack of love was the cause of my depression, lack of motivation and unfulfillment in general. The thing is that I listened to your advice and tried to be happy with my life and it appears that is has been just a mask and since a few days ago, I started feeling unfulfilled once again. I don't know, it seems that something just clicked and I went blanked and watched my 2 other friends have fun and I just didn't find any of their small talk funny. And now it happens ever time I go out, nothing is fun. Today I watched the funniest scene from one of my favorite comedy with my friends and I barely laughed and to be clear I used to loose my breath sometimes while watching it and this is just an example. And I could just keep telling you how nothing is fun and I can't feel joy and that is the main problem. I feel like a blank canvas, like a ghost among my friends there is little fun in big things and no fun in small stuff at all. Even my best ( female ) friend told me that I am anxious and that I should enjoy life. Just a few days ago we used to text each other till 3 or 4 am but I realized that our talks became repetitive and that I just talked about dieting and gym and we even placed the bet. If I talk about diet or gym or fitness till the end of the month I loose. I am not obsessed with fitness or anything but it just seems that I have noting to talk about. And if I tried to go out and do something fun so I have something to talk about, it just isn't fun. You get the point I am unfulfilled and so noting is fun but then I don't have what to talk about and no matter how hard I tried nothing worked. You get the point by now. And I tried a lot of things : Going outside as much as I could, texted my friends and family, watched yt video for confidence, anxiety, social anxiety, on how to be funnier, things to improve me as a person in general. I am becoming afraid that I will become an simple minded creature with no joy in life or friends or anything. I don't feel that I am going to go mad, I never found myself as a mentally unstable person just because of how much I think about thing and I always think of myself as a thinker, you get the idea ( overthinking might be one of the causes?). The meaning of my last sentence is that this is my last hope and that if nobody here can help me even a bit, I will be forced to tell my mom and then I will have to see a psychologist and I really don't want to take it to the level of being looked at as a person with great mental problem. You good people are my last hope, if you could tell me what is the cause or the causes of this and if you could give me a routine or some tips that could help me get rid of this "curse" I would be grateful to you for life. Fell 100% free to ask anything personal because I really have to clear this out.I apologize for my half decent English and if you helped me I would be happy to do you a favor as long as it is in my power. I can't give you any money because I am 15 and I don't have any but I could give my best to help you with anything. You see I just want to get trough this and I don't see the light at the end of the tunnel. And again feel free to ask anything and thank you in advance!