I have been obsessed with The Gathering since I discovered them in 2009, and they are probably my favourite band now, as shown here http://www.last.fm/user/johngebreadman I like all eras of their music, from their first death/doom album, to their new single released with new singer Silje. Anneke Van Giersbergen is easily my favourite singer of all time, which is one of the reasons I enjoy their music so much, but the music as well is excellent, with them doing something significantly different album after album.

Anything similar to any era of the gathering would be great, not sure why I never asked for anything before, anything similar to my favourite band would be appreciated

I haven't listened to a ton of The Gathering(I have How to Measure a Planet?, but that's it), but one band you might enjoy is Subrosa: http://www.youtube.com/watch?v=Ivx1HrKqMpQ

Female vocals, dark imagery, very somber.

Have you checked Silje's previous band Octavia Sperati? It's very close to Mandilyon era Gathering

Yes I have, it's pretty good. And I didn't like Subrosa much, stoner doom really isn't my thing (yet I love early sabbath)

The 3rd and the Mortal maybe.

check out the dutch death/doom scene
sempiternal deathreign, spina bifida, castles and ofcourse asphyx.

I've heard Tears Laid in Earth, and it's a great album. Should I try their others?

Definitely the debut EP if you liked that one. I wholeheartedly recommend Painting on Glass if you have a taste for great non-metal, too.