If it makes it easier, why don't you try playing with more cards in hand?
Then, once you've managed to succeed many times, reduce the number of cards you have in your hand.
But all in all I agree with Sam & Mr Taylor: it gets much more intense when playing with multiple players.
We even played a 6-players-game today (not officially supported) and managed to play all cards on our second try.
Yes, in a Solo variant, it look like Patience.
And I agree with ThoMoute and the others.
I played recently a 2 players game with 7 cards in habd, because he never played, then asked me to play another one more difficult with 6 cards. Try to find a friend(s), family member or a coworker who might enjoy the task and fight the difficulty.
BTW a very good shuffling make the game harder
Not like certain friend shuffling style (cut twice and it is done)