I feel for you, and for myself for having suffered similar indignities. Yes, it is absolutely abuse, and in my case also was accompanied by abuse in other forms, mainly verbal and psychological. The damage to the marriage was beyond repair.
It's good to understand the insecurities that underlie the need to snoop. They are the same as drive other boundary violations--an incomplete or damaged self that cannot bear to let the other be an autonomous individual. But if not surmounted (a good therapist can make the difference) they will undermine the trust upon which love depends.