Maybe you find it hard to be honest with God because you think He won't want to hear your complaints?
I find the psalms helpful in this. They remind me that God's chosen poets and musicians, even his beloved king David among them, had some very bad days.
There are some psalms which we read in church but leave huge chunks out, because we think they're "not very nice."
But they're in the Bible for a purpose.
God made sure they got put in, because they show us that all human emotions are acceptable, even the horrible ones, SO LONG AS we bring them to God for help, rather than letting them fester.
There are some really vengeful thoughts vented there, but when you continue on reading, you find that the writer speaks his mind, then works through the issue.
By the end, even if all is still not resolved, the writer has still managed to say something along the lines of : "Oh Lord, life is just so awful, but You are God and I will trust you even so."
Don't know if that's any use to you, but I hope so.
Another thing I enjoy when I can't pray is to sing a worship song or hymn, or even listen to others doing so. I suppose the best of them are modern psalms!
You are showing a willing heart by coming here and asking.
Do you realise; that in itself is pleasing to God?
Now just don't give up and let it drop. He is holding on to you.
God bless, Susana