help with my fondant recipe please.

Have you tried kneading is some Tylose. This is what I do when I need my fondant to firm up and dry quickly.

Need more info. What is "buttercream fondant"? If you are talking about rolled buttercream, I don't think it is ever going to do what you want it to do no matter how much tylose you add to it. For figure molding you need fondant , gumpaste or candy clay or a mix of the above. What you are trying to do is the equivalent of trying to pipe a tiara out of buttercream instead of royal icing and expecting it to stand up on its own.

If you are talking about some other product, I don't know what the fix would be for your issue.

I think she means the butter cream flavored fondant recipe.

What you need is a good gumpaste recipe. Mixing gumpaste into buttercream fondant will never be strong enough for what you are doing. The large amount of butter weakens the structure. If you mixed tylose into a regular fondant it would be better but still not as good as a true gumplaste recipe. Here is my favourite:

Egg White Gumpaste (Flower paste)
2 large egg whites
8 cups icing sugar
1 1/2 teaspoons of karaya gum (GumTex)
1/4 cup warm water (Tap water is fine. It should not feel hot to touch)
1 tablespoon shortening (Does not go into gumpaste but is used to work with it)
1. In a medium bowl beat egg whites with an electric mixer until frothy (about 30-40 seconds).
2. Add 2 1/2 cups icing sugar and beat until well combined.
3. Sprinkle the karaya gum on top of the mixture and then beat again for about 15 seconds. Beat in another 2 1/2 cups of icing sugar. The mixture will be dry and crumbly.
4. Add 1/4 cup warm water and mix until smooth.
5. Put the final 3 cups of icing sugar in the bowl and knead in by hand. You may have to take the gum paste out of the bowl and continue kneading.
Note: This gumpaste is a nice white color and it is ready to use immediately if you use shortening on your hands when you work with it. It will be even easier to work with if you allow it to sit overnight in a airtight plastic bag or container. This gumpaste works beautifully in silicon molds. It is my favorite gum paste recipe and dries very light and strong. Makes 2.5 cups of gum paste.
If you like this recipe have a look at my ebook cookbook called "Icing Only" on Kindle and Kobo.