Oh wow! You are very resourceful in your actions of breaking up your H's affair! HOWEVER; don't be fooled into thinking that the truth will not come out eventually!!
You are feeling guilty about the deception and trickery you have done. Because of what you have done, your H came clean. I am sure it would have been awhile (or never) for him to confess to what went on over seas.
I think you do need to come clean. Living with lies is going to wear on your health, both physically and emotionally. I am not judging you, I have been there and the feelings of desperation are overwhelming.
If your H and you are reworking/rebuilding your M, you should do so with a clean slate...this is just my opinion but one thing I learned being on these boards is that snooping and obtaining information through deceptive means only hurts us in the end.
I know you did what you did to save your marriage...and you can't beat yourself up over that. We all make mistakes, but forgiving and admitting to them makes you a strong, brave person!