Perhaps it is a matter of preference, and only the OP knows his situation well enough to determine whether confession will be accepted and forgiven.
In the 12-step program that I facilitate, the way they discuss confession is that they confess unless it would harm them or others. This kind of situation is a tricky one because by telling, harm will be done to her and possibly to their children (if it goes as far as a divorce). But if he does not tell, there could be harm to her by him feeding it more and more and developing an addiction. I think in the case of the OP, since we don't have many details to work from, it would be wise to talk to an elder in the church who he knows and can trust, and work it out with him.
If the OP decides to confess to his wife, hopefully he will be prepared to go all the way with the reconciliation - that is, confess, acknowledge how (specifically) it hurt your wife, ask her to forgive you, and then explain that you are prepared for whatever consequences come from what you did. It needs to be spoken with sincerity that can only come from true sorrow for having hurt her.
I have to say to the OP that if he is 25 and has never looked at inappropriate content before, good for him! After all, it's all over the net, and surely he has been on the net all his life. But....the OP is edited, and I thought I had read that he had been drunk, so one way to prevent looking again is to not drink too much anymore (if that's what happened).
The other part of this is the OP's claim that he is evil, demonic. This is a lie, so don't believe it! All sin is evil, and we all sin. Our righteousness is in Christ Jesus, so that's why we need to stay fixed on him! But if we as Christians still sin, that does not mean WE are evil. It means that we have fallen short and must run to Jesus for his righteousness.