Exhusted

I'm honestly so exhausted at the moment. My mind is all over the place and I feel extremely depressed at the moment. I'm about to turn 30 and I've never had a serious relationship, and I struggle to keep friends. I also struggle to meet new people because I'm such an introvert. I have 1 really good friend and have realized if i stop reaching out to people they don't reach out to me. and honestly, I'm so tired of being a friend of convenience to people. I always give so much of myself to people and feel like no one ever really appreciates me that much. I'm away for course at the moment and my best friend is on deployment, so I haven't seen them in quiet a few weeks. and currently it's been 2 weeks since I actually hung out with someone which makes me feel so lonely. I feel like I don't actually mean that much to anyone and I feel so isolated. I've been trying to get fitter and lose weight this year and when I am really struggling with my mind, I end up losing motivation for a little bit which doesn't help me. But I just feel so alone and have no one to talk to. I have my mum which is great, but she doesn't know how much I'm struggling within my own mind.