Unfortunately, the default position of a lot of women who give advice here seems to be to LTB at the first sign of any problems.
''when we do have sex we follow the same routine and I want to get out of that and enjoy good sex for a long time''
I'm a bit confused here. Is your problem that it currently isn't very good or that you want it to be even more exciting.
There's absolutely nothing wrong with routine when you enjoy what you're doing.
A huge part of maintaining a relationship is honest communication. Have you raised any of this with your DP? It can be very difficult for some people to talk honestly about very intimate issues, but you really do need to be able to do this with your DP.
Perhaps your DP is also dissatisfied with the situation but doesn't know how to broach it with you?
Adding some excitement doesn't always have to mean doing new things - and, by the way, I'm totally with you on not wanting to do anal.
As Jan45 says above, being spontaneous yourself is a good thing. There is nothing stopping you initiating sex whenever you want. Wear some sexy clothes or underwear and just drag him off to the bedroom.
Although, of course, he is also entitled to have a ''headache'' if he doesn't feel like it. But, too many ''headaches'' and you might want to have more of a conversation about what is going on.
Another thing to think about is fantasies. To me, fantasies fall in to two categories:-
1 Fantasies that I think I would really like to have come real.
2 Fantasies that, although being incredibly erotic, I know that I would never want to happen in real life
Talk openly with your DP about any fantasies that either of you have that come under the first category and think about ways of incorporating them in what you do.
For example, and this may be way TMI, me and DH sometimes do a sort of ''naughty masseur'' thing where he gives me a massage before having his wicked way with me.
This works for me on a number of levels, not least that that DH is now really good at giving me a fantastic erotic massage 
Then, at other times, we do things that really press his buttons. It's only fair if sometimes he's giving me an hour long massage that I do things for him at other times.
So, please have a chat with your DP and don't be afraid to initiate things.