You had mentioned that you think your wife may have another man in her life now, thus the cold shouldering of you. Let's assume that she has - what are you going to do with it?
Give her up? Why be a loser? You were born a winner. Of all the sperms your dad had, ONLY you managed to fertilize the egg & came into this World. You had won her over, enough to get married & have a kid. She certainly loves you. So why give up on that love & surrender her to another man & admit defeat?
Some sweet talking men looking for flings would go after married women because:-
A)married women has strings attached - to her family & kids. Dumping her after a fling is easier as such women would have a hard time giving up everything.
B)married women are cleaner than women in the sexual trade. Those women have sexual intercourse with at least 10men per day, but the married women may not even had sexual intercourse with anyone over a year.
A woman has her needs, just like you - love, intimacy, appreciation & affection. Most men after marriage presume she had already been won over, & thus start to neglect her in many ways unlike the days of courtship - attention, devotion, etc. No more romantic dates. No more tenderness & sweet talk over the phone, etc.
Instead, after work, she has to prepare dinner, wash the dishes, wash the clothes, attend to the baby, no one to share her woes & any sharing are deemed as complaints or nagging.
Perhaps, take a time-out & reflect. You are born a winner. You can win her back. She may just be wondering...where is the love?