Have I made a mistake?

What should I do here?

I got married almost 2 years ago to a woman that I loved. She has a son that I get along with and care about and who loves me.........but I think they both love me more than I love them. I don't know what to do for the best here.

I made a mistake a year ago when started an affair with someone I met through work. I should never have done it, I don't know why I did it but I enjoyed it while it was happening and I didn't do anything to stop it. I slept with her twice and I've had feelings of guilt since the event but I don't know what to do. I think there's something wrong with me as if I found myself in that position again I'd most likely not stop myself.

If my wife knew about it I'd obviously be out the door and homeless, leaving her to pick up the pieces of our failed marriage with a heartbroken, angry and confused 12 yr old wondering why his stepdad could ever do that to his mum. It's a right old mess.

We have a lovely house with lots of nice things and without me she stands to lose it all as the lifestyle we lead can only be sustained by a joint wage.

We have awful neighbours on one side who would like nothing more than to see our life crash around us (as we wish the same on them and worse) so if I left the humiliation would be unbearable for all involved.

I really have fucked it all up completely and altho as it stands I'm unlikely to get found out as it's all over now, I'm still waiting for that day when she'll talk to someone I don't expect and she'll discover the lies and secrets. I never used to keep anything from her but it's all changed now.

I'm addicted to a computer game that I play constantly and she feels neglected but we never go out anywhere, even when i ask her she says she'd rather stay in and chill. Then she moans that we never do anything.

I feel trapped and stagnant. Before I met her I liked to do active things but she won't do anything like that and has put on loads of weight since then so that I don't even fancy her anymore.

I don't know what to do or what the solution is.