I'm 23yrs old virgin. I've never had any sexual or physical contact with a girl. I know how most men masturbate, but the way I do it is different, i lie down on my stomach and rub my penis on the bed or press hard with my hand to ejaculate. And in less than a minute i ejaculate.
Please is there anything wrong with my method?
Nothing wrong, we all masturbate differently and the important thing is that it feels good for you! That's what masturbating is all about! 
Normal don't worry, as they say what ever floats the Boat, healthy habit
No it's normal as long as you enjoy it that's all that matters there will be some body our for you
Guessing you're circumcised? Often needs a little more stimulation than uncut. Not a problem however you do it but when you do get with women she may enjoy jerking you off too and you can't expect her to hold the mattress 
If you need to see lots of various other techniques (including yours, you're not alone doing it this way) try Reddit r/jacking. Just enjoy it however you do it.
nope ,i do on the bed ,sometimes over the table
As long as you enjoy it it’ll be ok.
One word of warning though, like others have hinted at.
If you get too used to doing it a certain way, no matter what way, it may become difficult in any other position.
That’s why death grip can be such an issue. You get used to a certain amount of pressure/friction before you can orgasm and if you do t get that magic combination it’s just not going to happen.
My first lover taught me a valuable lesson when she refused to Jack me off. She said that I’d had years of practice with my own body and that she’d had a little more than zero. A wise woman indeed.
I suggest that you change things up regularly. If you need to pound your mattress to finish then ok. Just start by using your hand. Then try using your other hand. Then your main hand backwards. You get the picture. It took me until I was 30 before I could masturbate with my left hand. Now it’s second nature. I used to give up because things weren’t the same as usual and I didn’t know that that was a bad thing. There was no internet or Reddit to guide me back then.
Yes I do the same on a mattress... Would be interested to hear of other ways to Masturbate
Sex or masturbation
Circumcision, bruising after masturbation 
Masturbation
