You are from an age group that is by and large missing in most Lutheran congregations. Part of this is a result of people gone at college, life in constant transition (even yourself being married - congrats by the way), and so forth makes this group mostly absent.
Lutherans tend to worship in a style that many 20 year olds do not wish to participate in for various reasons. Some of them in later years tend to return to the Lutheran church for this reason or that. But it does make it lonely for those of that group who remain. What this tends to do is shoo away those who did attend but are left with no peers.
To this I say several things. First is to encourage you, for your place in the church is not marked by how well you blend in but by the invitation and forgiveness of Christ and the Holy Spirit who has called you by the Gospel. The next is to say this is the importance of learning to connect to people outside our age group. Sunday mornings tend to be segregated in every way - class, race, age, and color, because we feel comfortable with our peers. But church is a family gathering, where we belong even with the older aunts and great grandparents. It is the family of God gathered around the word of Jesus. And so it is good to come with that attitude and to live into that conviction by cross-generational connection. Finally it is to commission you, for the community of believers. Your willingness to stick around will be important for helping the next 20 yr old who walks in that church to not feel alone and to connect to the whole community.
As younger people we can complain the church is older, we don't fit in. But if we leave, then the next young person will walk in and say the same thing. If we want more youth in the church we need to be willing to be there, otherwise we shouldn't expect a church to have young people.
Stay with it, connect with some of the wonderful elder members of the body of Christ, and in all things may the Lord be with you.