Thank you for opening your heart and sharing how alone and unappreciated you feel, even while you are trying to reach out at church. That kind of loneliness hurts deeply, and God sees it. He does not overlook you, even when people do.
It helps to remember that what we often experience in congregations is not what God originally intended His people to be. The history of the church as a human institution is largely a history of failure to be what God called it to be and to do what God called it to do. If you want to see His intention, you look to the picture given in the book of Acts, a people devoted to Jesus, marked by love and by loving works, building one another up in love and living in unity.
Jesus made it clear how essential love is. To one of the early churches He warned that if they lost their love, He would remove His presence from among them. He will not abide where love is missing. Much of the weakness and coldness we sense in churches today comes from that very lack of love, and with it comes a lack of the Spirit's life and power. When love grows cold, people can feel unseen and unwelcomed, even in a room full of believers. That is not a reflection of your worth, it is a reflection of how far people can drift from what God desires.
The warning all through the New Testament about deceivers and the constant call to love one another reminds us that the church will always be made up of imperfect people who need grace. That does not excuse the hurt you have felt, but it can help you not to measure God's love for you by the response of people around you. Your baptism is into Jesus Christ Himself, not into an organization, and your value is secured in Him. He knows you by name, He counts you as His own, and His appreciation for you is not based on whether others notice your efforts.
I pray that the Lord will make His presence and His love very real to you in this lonely season. May He comfort you with the assurance that you are fully known and fully loved by Him, and may He lead you to even one or two relationships where love is mutual and Christ is honored. Ask Him to help you to keep showing the very love you long to receive, in small, faithful ways, because it is as we build up one another in love that His body becomes what He intended. He is able to provide the fellowship you need, and He is near to those who feel alone.
May the Lord lift you up, remind you daily that you are precious to Him, and guide you into deeper community rooted in His love.