If you are not the affectionate type, then you may consider changing your perspective on the matter.  You if you want to increase her passion and boost her libido, then she has to feel loved.  And a reasonable amount of affection goes a long way towards making your wife feel loved.

Showing affection does not take a lot of work.  And although snuggling is affectionate, there are many other ways to show affection and love to your wife.  It's in the little things. Here are some ideas that on the surface seem obvious, but many men simply don't think of them at the time:

• When you're walking together, don't outrun her - wait up, slow down - walk with her
• Hold her hand while walking
• When you're driving, caress the nape of her neck or hold her hand
• When sitting on the couch, invite her to lay her head on your lap and run your fingers through her hair
• At dinner, lightly touch her foot with yours
• In bed: spoon
• When she's doing some house work or cooking, come up and give a little kiss on her cheek or neck
• Hug her
• Kiss her goodbye
• Kiss her hello
• Hug her when you see her at the end of the day

These are little things.  They are not difficult - just remember to do them - make a little effort.  It's all about that little random physical touch that lets her know you want to be with her.  This reinforces that you love her and makes her feel loved on a deeper level.

By design, women need to feel loved.  The more she feels loved, the more passionate she will be, the more she'll desire you, the more secure she will feel, and the more her libido will grow.  The result is that your sex life will get much better.  And your relationship will improve.