Hey....my favourite topic!!! Lol
As you've just found out...asking for practical advice on a forum just results in lots of opinions on the practice itself...and before you know it your not getting the info you need...
People who are not waking up in the early hours before dawn to do their simran shouldn't reply on a forum that is asking about practical help on waking up during these hours to do Simran...
It's like asking how best to do a three point turn and them getting replies from people that don't drive...
Anyway ji...all I can say is...keep doing it...you won't ever regret it!
I have such difficulties from time to time even after a few years of doing simran in the early hours...
As the other poster said...change your diet maybe...eat a few hours before sleeping...
Also I find doing Simran before you sleep helps...with your sleep and also getting up at amrit vela...
Keep doing you internal ardaas asking for His support...and again like in the last posts...you need to have the love, that pull from.within...and then you.ll get up no matter what 
If you still can't manage it...dont beat yourself up...keep doing it in the daytime and before sleep...
But I have to say...nothing compares with the early hours...its only when I started this, that everything went BOOOM. Life was never the same since..
Message me direct if you want...happy to.discuss in more details if you want..
