It sounds like you're definitely leaning toward Wicca, becase the idea of a female Deity is very Wiccan and not at all to be found in Christianity.
As a Wiccan, there would be nothing stopping you from attending a Catholic mass, so long as you act respectfully within their temples. Our religion doesn't dissolve when it comes into contact with others. :-)
Getting closer to God/dess as a Wiccan is entirely a matter of starting to practice the religion on a daily basis. I recommend the book "Wicca: A Guide for the Solitary Practitioner" by Scott Cunningham; it will give you all the information you need to get started. Then it's a matter of honoring the Lord and the Lady as often and as sincerely as you can.
You might also try contacting other Wiccans in your area in order to attend public rituals, open circles, and so on. One way to do this is through the Witches of the World section at Witchvox:
http://www.witchvox.com/xvn.html
Just use the pull-down menus on the left to find individuals, groups, shops, and events in your area.
Best of luck to you on your path.
EDITED TO ADD: In response to a previous poster... Christianity and Wicca don't play well together, for reasons outlined in the following article:
http://wicca.timerift.net/christianwicca.shtml
In fact, you'll find the http://wicca.timerift.net site as a whole is an excellent resource.