Each day, read and believe Romans 8:14-17
For you did not receive the spirit of slavery to fall back into fear, but you have received the Spirit of adoption as sons, by whom we cry, “Abba! Father!” The Spirit himself bears witness with our spirit that we are children of God, and if children, then heirs—heirs of God and fellow heirs with Christ, provided we suffer with him in order that we may also be glorified with him. Romans 8:14-17
Then, ask God to strengthen the conviction in your heart that you are His son or daughter and His heir with Christ.
And...rebuke any lies that come to your heart or mind that tell you you don't deserve this, and therefore you shouldn't receive it. Remember, this does not have anything to do with what you deserve. It has everything to do with what God did for you in spite of the fact that you didn't deserve it.
God shows his love for us in that while we were still sinners, Christ died for us.
Romans 5:8
Jesus thought this was worth dying for.
Certainly it is worth you fighting for.