WILD Attempt what did I do wrong and what happened

(First off I have became lucid 5 times and 4 out of the 5 I woke up a few seconds later or went back to normal dreaming. Only one of the 5 lasted a few minutes.) Ok so I set my alarm for 6 hours after i'm about to fall asleep and did a WBTB. I only did a quick WBTB though (like 30 sec) then attempted WILD. I laid down on my left shoulder and stayed completely still. I started breathing deeply and calmly. I repeated the phrase I am lucid to myself every few second to keep myself awake and to help with becoming lucid. (I said this in the present tense because I heard it help more rather than saying I will become lucid.) After awhile my left arm started feeling heavy. After awhile it was really heavy and both my legs started getting heavier. A little while later my left arm and both legs were really heavy and started aching. The aching grew until I could barely stand it. Even though I didn't start experiencing hypnagogia and was in pain I kept at it for awhile keeping myself completely still with my eyes closed and repeating my phrase. After awhile of nothing happening and the really intense aching I opened my eyes and gave up. I checked my alarm and I from start to finish I had been at it for an hour and a half. (BTW fell asleep at 9:30 alarm woke me up at 3:30 and first attempt ended at 5:00) After that I try again and lay on my back. I relax myself, close my eyes, and repeat my phrase. This time my both m arms and only my arms started becoming heavy. They didn't become as heavy or ache like last attempt though. Soon I drifted off (didn't work) just having a regular dream when I remember I was attempting WILD and became lucid. I am now back in my bed and feel like I am separating from my physical body and when I think i'm about to have a good lucid I wake up. As soon as i am awake I hear my brothers loud TV which is what might have waken me. Or it could have just been I became to exited or something. (It is now 5:25 so my second attempt and my dream/lucidity lasted 25 minutes) So what I want to know is if I did anything wrong and why parts of my body become heavy and sometimes hurt like that.

Welcome to the forum!

It's sounds like you were definitely on the right track. Don't worry about not experiencing hypnagogia - it's a good indicator you're getting close, but it doesn't always happen, so don't distract yourself by waiting for it to happen. As for the aching, if I had to guess I'd say it was just the position you were in. Your position for WILD really doesn't matter a whole lot, so just sleep in whatever position feels comfortable.

I'd also suggest not dragging your attempt on for as long as you did. There's not really a reason to stretch it out for an hour and a half - usually, if you can't get it within 30 minutes or so, it's probably just best to give up on your intense focus and just get comfortable and go to sleep. Since WILD is mainly a mindset you're setting, just going to sleep after attempting WILD can often keep you in that mindset and can, as you experienced in the second attempt, increase your chances of a DILD. Obviously, you can't lucid dream if you can't fall asleep, so if WILD's really keeping you up that long, it's more beneficial to cut it short and just get some sleep.