How to look at the bright side of the things?

Well, I don’t know where to start or how to start. The only thing I know is that I am both lucky and unlucky. I am lucky because I have a great family and friends that I can rely on. I have the great job that I’ve been dreaming of and well let’s just say wonderful colleagues that I hang on almost every each day and night. My job pays me a good salary and I am thankful for it. Plus, my family pays my rent and a lot of additionals. Moreover, they encourage me to see the world. Thanks to them, I had visited lots of European Country. So, it’s clearly, I have a great life. As mentioned above, I am truly, deeply, thankful and grateful for my life.
You may ask why I feel unlucky. I don’t have any siblings. Eventhough I grew up in a big blessed family, I feel the deficiency of love. I know that there is nothing I can do. But sometimes I find myself more and more viscerally excited by the level of interest that has been shown by my friends/people. Secondly, I am 28 years old girl whose never ever had a relationship before. Well just flings. I’ve waiting this long to get a relationship for nothing! Yet no one seems to appear on my door. One can say I have high standards and should have lowered it. Someone else can say I give the wrong vibe. Well, it was true then I lowered my expectation and tried to be positive all the time, like smiling, trying to communicate etc. And later I criticized myself, beat myself up, felt sorry for myself for not being able to have a relationship! Well I am here, standing still. And I started to feel like I cannot hold onto the life since almost all of my friends are getting engage or marry. It feels like I am forever alone and I don’t want to be! I do have a beautiful dream about my future life. Especially I do want to have babies. I am really depressed, indeed but happy at the same time. I can deal with life but not knowing what life will bring it to me makes it harsh. Lastly, I suppose all the negative thoughts are on my mind because I live alone and my brain tricks me, mocks me all time. It made me believe that I stuck in a rat and nothing will ever change.