@newporty,
As a woman who has been cheated on, I think you should tell your wife the truth and your reasons for it, in as gentle a way as possible. Start by telling her that you do love her. If you are unsure of her reaction, have the discussion in a public place.
Before you tell her however, have a good think about the following:
Did you have sex with your wife prior to getting married? If so, what was sex with her like then?
If it was good, why is not good now? Can the reasons why it is not good now be worked on?
If it is was not good.... why did you marry her?
Have you ever had an honest and open discussion with your wife regarding your sex lives? Have you ever asked her to do those things these other women do for you? Maybe she is as bored with you as you are with her. If she is unskilled at certain things you like. Teach her, with kindness, in a non critical way. She too should teach you what she enjoys.
Sex and intimacy, especially for women, are two different things and many men fail to understand that. You can have sex with someone amd do all linds of intimate acts and yet have no real connection. You can be intimate with and love somebody without even having sex. Women usually want both great sex and intimacy with their husband.
What you refer to as "chemistry" may simply be the thrill of the chase. Conquering a new partner. An ego boost. After being with the one person for a while, even amazing "chemistry" can get old. Then, what is left?
True love does not have to be about sex and great sex does not always mean that you have found genuine love. Love is hard to find. If you and your wife love each other, then don't throw it away. You will both regret it. Your wife may even be longing to be able to do for you what these other women do.
The fact that you have been with others will hurt her, but not as much as you continuing to lie will hurt her. If you are even considering continuing your marriage, then you must be honest with her in order to rebuild trust between the two of you. Without trust, interactions between you will become more negative over time. Your wife also deserves to know the truth in order to decide if she can live with your dark side.
Ask yourself this also... Are you the type of man who would still want to be with others on the side no matter who you are with? Do you get bored easily? Do you like the thrill of the chase?
There is nothing wrong with being like that, but if you are, then you need to be honest, first with yourself and then with whoever you are with.
We women have good intuition. We can sense when something is not right. Lying to us can cause psychological damage and low self esteem.
Please... have the courage to be honest with your wife and if things don't work out... have the courage to be honest in your future dealings with women. There are women who enjoy an open relationship. Perhaps you should be with one of them them. In order for a woman to really love you, she must know who you really are.
Peace and best wishes.