Is it impossible for me to get energy from sleep if I have restless leg syndrome?

No. There are effective treatments for restless leg. Talk to a sleep specialist to make sure there are no other conditions affecting your sleep.
RLS . Rls is a syndrome you feel when you're awake. You may be describing periodic limb movement disorder of sleep. Sometimes link jerking during sleep may cause arousals and fragment your sleep so the depth and quality are not as good. An attended polysomnogram aka sleep study would let you know.
Maybe. If your are experiencing arousals from the RLS then yoir sleep may not be giving you the rest and recovery needed to feel energetic. You probably need to see a sleep physician. The only way to tell how much sleep you are getting from your time in bed is to have a sleep study.

Related Questions

I can't sleep I have restless leg syndrome how can I relieved the pain?

Restless legs. If you have restless legs, it may help you to use iron supplements with vitamin C, or to use a medicine that contains dopamine, such as pramipexole or ropinirole. First it is helpful to know if this is the cause of your leg symptoms (or if there is another cause) and what your iron level (ferritin) is. Read more...