Snodreliss has down. Do NOT slowplay NL5! It's tempting because you think maybe you won't get paid off by betting too big, but this is not true.
Think of it like this; if you bet big and they fold, they likely had nothing anyway, so you don't win much this time. Don't worry about it, you'll raise QQ or whatever again and hit a set in the usual 3 or 4-way pot, just bet hard and you'll be amazed at what they will get it all in with. Gets funny after a while. 
On the flip side, in a multiway pot and A high flop or co-ordinated board, don't bother calling down with QQ or KK if there is action, you're done, fold it out (most times) unless you know your enemy well (it gets easier after a few zillion hands :))
Also, I suspect that some of your bad beats and suckouts will be due to your play - they certainly are for me that's for sure! Post some hands on the forums and you will soon get good advice on how to play in certain situations; there're good people on here.
Watch coaching sessions and vids and see how often the coach slowplays big hands. I guarantee...very very rarely. Read the articles too, they helped me so much I went from a 'No Idea' and winning a little bit, to owning the NL5s for 2 years now. It's a fun level.
Once you get the hang of it and look back, you'll wonder what all the fuss was about! 
Have fun.