It sounds to me like you just aren't leaving sufficient room in the pan - you're crowding it.
When you drop food into the fryer, in the first few seconds there should be enough heat to seal the outside - this is vital for anything battered, but still important for such as fries.
If your heat drops too far because the pan is too crowded, this won't happen. To make matters worse, as it all sits in a lump trying to regain temperature, the starches in the potatoes start to set, gluing the individual fries together & also to the pan.
If finances won't allow a double-size pan - non-stick shouldn't be necessary for a deep-fryer - then try frying in two or even three batches instead, which will allow you to keep the heat up & the fries separate. If they hit each other & the sides less, they'll stick less. Stirring shouldn't be quite so necessary either, if they have enough room to move, one or two gentle swirls during the cook should be plenty.