Write out the truths from God's word and recite them often if necessary until they become a part of your beliefs. Pray and ask God to help you truly believe them. That's the kind of prayer He delights in answering!
Why Should We Pray (if God already knows everything anyway)?
Worship brings God's manifest presence into your situation, lifts you up closer to Him & there you experience Him. It starts as an act of faith that you believe & are confident in all that He is & trust all that He is.