Help with mead

I have made a 1 gal batch with just water, my own honey and yeast(Dap) nutrient. I did add a little PM. It is about 3 weeks in the primary with 5 star Premier Cuvee.

Can I add fruit or anything to sweeten it?

I have 3 more qts of honey. It is a light spring floral from my gardens and wildflowers. I can collect some golden rod honey if need be. I have frozen fairly sweet peach slurry with just a little lemon juice and some frozen whole strawberries. I also have lemon balm, bee balm, rosemary, thyme, basil and some over herbs.

I also have Wyeast 3068 from Hefe yeast cake and 1332 from PA cake.

After searching, I just can't seem to figure out a good recipe besides running to the store for oranges, raisins or cider. If I can't improve the previous batch I would like to start a new 1 gal batch using what I grow.

From everything I read I should be able to rack the mead onto the peach slurry. I plan on 2 lbs slurry to 7/8 gal of 3 week old mead.

You can add fruit to sweeten but you want to make sure that the yeast in the mead is not going to convert the sugars in the fruit to alcohol so that it will end up just as dry as it is now. One way to do that is to ensure that the yeast colony is very depleted (racking every two months or so three or four times) AND then stabilizing the mead with K-meta and K-sorbate added in tandem. You can then safely add sweetener with no fear that the yeast will be able to ferment those sugars.

What I recently learned from experience (first batch of melomels)
Leave enough head space with the slurry. The escaping CO2 will create large gas pockets in the slurry, resulting in a bigger volume than you might expect.
Out of 5 melomels, the apple-slurry, banana-slurry and watermelon-slurry all caused blowouts and a fair amount of cleanup.
The cherry and blueberry were much more liquid and didn't have that problem.

I would first figure out the original gravity from the honey used. Also remember that you are using wine yeast, so it will take months to fully mature once the initial fermentation (sugar to alcohol conversion) has completed. If you want to sweeten the final result, you have to stabilize with KMetaBisulfite/KSorbate before sweetening.

If you rack onto the peach slurry you are just adding more sugar = alcohol. Your mead must be stabilized before you sweeten it to taste. Most people ferment to dry, stabilize then backsweeten to their preference.