If you have trouble trusting God it may be because you don’t really know him. If you know what He says to do, but you don’t do what He says, can you truthfully say you know Him?
If you know your wife, (and I think you do) and she says, “I don’t think we should go into debt to buy a boat.” Even though you want a boat, and you know you could probably buy one on credit and get away with it. But you also know your wife, and you know she’s usually right about the budget. So you relent because you trust her.
Perhaps you know God says, “Sex is something beautiful I designed specifically and exclusively for marriage”, yet you decide to ignore his instruction. You’ve just decided to trust your own limited thinking over God’s infinite wisdom. Why? It might be because you don’t really know Him well enough to trust Him.
To know God is to trust Him.