The 26-year-old joined Sunderland in a £9million move from Hearts.
Gordon has had a nightmare season, first losing his No1 spot at Sunderland and yesterday he was dropped from Scotland’s World Cup qualifier in Holland.
Gordon said: “It is the first time this has happened in my career. It is very difficult to be patient. There is frustration and anger. It is horrible just sitting there.
“It’s not about ego. If your ability makes you the best, if your technique is the best, then you should be playing. I am still very confident that I can be the No 1 and I will give a good account of myself the next time I get a chance.
“But it has been a very difficult thing to face up to. I have sat in bed some nights till two or three in the morning not being able to sleep.
“I’ve had nights where I’ve not slept at all, thinking: ‘What am I going to do? Who can I speak to?’ There’s no off switch. You just have to find a way to deal with it.
“In the dressing-room before a game is probably the hardest point. The guys are getting ready to do battle but you’re not involved.
“Marton has signed a new contract as well. We’re both here for the next three years and neither of us would be happy being second choice.
“There are definitely going to be problems at some point. I want to get back in the first team but I would eventually consider my future if it came to that. There is not a lot I can do about it right now.”