At 22 he is still a kid. You will have to be patient and slowly enable him to grow up into a man.
He is insecure. He is calling you because he is afraid YOU will cheat if he doesn't keep you occupied by talking with him. Try getting him to stop calling you and to focus on his work. He can talk with you when he gets home. Take a class or get a job so he knows where you are and knows he can't call. (Teach him to trust that you will not cheat on him. Tell him you'd never cheat on him and also tell him that if he ever cheated or abused you that you would leave him.)
The play station is an escape from reality. Very slowly limit the play station evenings from every night to just once or twice a week. Don't make it a rule, just start scheduling other things you can do together, like a movie night, going on walks, cooking together, taking an evening class or whatever interests the two of you. Make them routines so he knows what to expect each night.
Start playing the games with him so it is no longer an escape into a solo
fantasy universe but becomes an activity that includes both of you.
On spicing up the bedroom: the bedroom should be free from distractions. No television. No game machine. It should be equally masculine and feminine so both are comfortable. Bedrooms are for only two things, sleeping and sex... and hopefully not in that order.
Some people prefer sex in the evening and others in the morning. Approach him at the time he prefers and see if you can make it a routine. On occassion, plant some seeds in his mind by whispering what you might do to him (or what he might do to you) 12 hours beforehand. "In the morning..."
Sex involves having confidence in yourself. Build up his confidence. Discuss his successes at work and how proud you are of him. You have confidence in yourself and can give him confidence by telling him how proud you are of him for specific traits or actions he does.
In the end, he has to want to change. All you can do is to give him the incentive and assist in the process.