My powers are gone! Why?

Thinking back 4 years, I notice how good I was at lucid dreaming. In the summer I could have DILDs nearly every night, WBTBs when I didn't DILD, and now that I think of it, WILD every couple of days in the morning. I never needed a reality check, never had to stabalize, barely had trouble controlling anything.
I took a year and a half off, but started again after discovering dreamviews and I have been trying to regain that control and ease of lucid dreaming ever since.
It seems that now I rarely have a DILD, dreams are unstable and I wake up soon after becoming lucid, and I have had two WILDs since starting back up. My dream recall has also fallen.
4 years ago I had no idea what I was doing, but could do anything I wanted. Now, I actually know what it was I was/am trying to do, but I can barely keep a dream going longer than a few minutes.

If any of you could offer any ideas as to why my skills disappeared, I would appreciate it.

you have to start from scratch. start by getting your recall up again. also.
has your sleep pattern changed? being on a regular sleep pattern will help a lot!
have you moved? you may have been more connected to a place and had a better ability to dream there. and then moved away and it stopped working as well. i don't know if that applies to you. but when i moved away from my mom's place i stopped dreaming as much. when i go back to visit, i often have lucid dreams again.
just go through and see what has changed in your life. on medication? dietary changes? relationships?