25 year old, all over muscle twitching and leg cramping, ALS? PLEASE HELP!

Hello, I am a 25 year old male. About a month ago I got a twitch in my right thumb. It didn't go away for about an hour. When I moved my thumb it stopped, but returned to twitching. Later the next day my arm started to get twitches. First just a few, then alot more. Its 4 weeks later and I am twitching all over. Mostly in my right calf, but in both calfs, upper legs, arms and fingers. As well as a few twitches on my stomach. I only get them when my muscles are at rest. Not when I'm using them. And mostly when I'm laying in bed to go to sleep. I originally thought it might be one of two anti-psychotic medications that my doctor had me try. But I only took each for about two days and stopped because I noticed the twitch in my thumb. So I still get twitches in my fingers and my legs and all over really.
I looked up twitching and now I think I have ALS. I have also noticed that my legs feel weird most of the time. The muscles get stiff really easily. I don't think I have any clinical weakness in my legs. I can run up stairs, jump on one leg, move my feet up and down and I don't have a problem with standing. I've gone for a quick jog and I notice my legs get tired easily. Although I know that I can keep running even though my legs get tired. I'm thinking its just perceived weakness. Plus I can't remember the last time I ran - I'm also a smoker.

I also weighed myself 3 days ago and I'm 130. Thats normal for me. I weighed myself again today and I weigh 127. I'm worried that I'm losing muscle mass because of ALS. Although I know going up and down a few pounds (even everyday is normal) I've only had these symptoms in the last month and I really can't say I have weak muscles. But I think I think I have weak legs muscles.

I talked to my GP and he wasn't worried at all. But in all honesty he is useless in most matters. I'm going to see a neruo on my suggestion to him.

Again, the twitching is everywhere - although mostly in my legs. AND I only noticed my legs until after I googled twitching and ALS came up. So I have the (what I hope is percieved muscle weakness) after the twitching.

Oh and right now my back hurts. Ugh.
Oh and my hands tremor sometimes but I'm also on seroquel which can cause that.

Can anyone help?
Thanks.

Do you think I have ALS?