Alternate picking can be such a frustrating technique because you develop the speed in another way than with many other techniques, in Alternate picking we develop the speed in quantum leaps instead of gradually getting faster. So a lot of people give up because they don't see the improvement they expect. But check out these five steps in this video and adjust any possible "wrong" way that has not taken you to the result you are after

Step 1. Practice at a pace where you have total control

Step 2. Avoid several lessons where you reach your maximum speed

Step 3. You must play fast or practice fast in at least one lesson(deeper explanation in the video)

Step 4. Keep a versatile practicing schedule

Step 5. Find your balance in updating your practicing schedule