I was recently diagnosed with Mitral Valve Prolapse and I get startled as im about to sleep.?

Can anybody help me? Just as im falling asleep, im startled awake and my heart races. There's like some muscle twitching going on sometimes and I'll try to sleep again but iim still having difficulty. Started happening about 2 weeks ago now. Am i suffering from anxiety, depression, hypnic jerk,, or what?... my tranquilizer does help but i dont want to be dependent on it forever...