Be More Direct. When all else fails, consider the direct approach. You may want to approach your wife and ask her what you could do to please her. Or ask her if you've done anything to upset her or turn her off. Before you do this, however, make sure you're willing to hear her answers. And be sure you're willing to work with her to work through whatever issues she believes might be going on. Best wishes.
Pay attention to her. If she is ignoring your overtures, pay attention to her (instead of trying to get her attention directed to you). See what needs doing at home and do it. Keep your word. Show up early. Be dependable, hardworking, steadfast. Also, seek your validation (for yourself) someplace other than your wife (be that in your own activities, your religion, art, etc). Good luck.
Try. May be she likes sildenafil?
Connect Intimately. I would sit down and talk to her. Honest communication is one of the most important things in building trust in a relationship. Positive intention behind the flowers and candy is helpful too. If your communication is strained then perhaps you could seek the help of a counselor/neutral party. It is vital that you strengthen your communication with your partner and do something fun together.