Sad to be an introvert

I’m super introverted. I’ve been shy all my life, but now in my adult life I’ve realized that I’m basically a loner. I have my husband and my toddler and my mom and one coworker that I have close to me and that’s basically all. Im no one’s best friend, most ppl don’t really seem to care too much for me. I’m a nice person I just don’t talk much, so I don’t give much conversation. It was my birthday last month and literally only two ppl wrote on my wall saying hbd. Yet for my siblings so much ppl including said hbd to them with our birthdays not being far apart. I got personal msgs which I’m trying to just focus on and be grateful more but it kind of makes me sad. Sometimes I wonder if it’s me. If I’m coming off as stuck up or something, or maybe because I don’t engage much. Kinda down at the moment.