My amp is giving feedbacks on high volume

I was playing my guitar last nite during a heavy rain, and my sound was completely swallowed by thunder and rain in my room..
(yes, i was crazy enough to play at the time)
Feeling unsatisfied for not being able to hear myself well on the speaker, i crank the volume up on my cheap amp only to get massive feedback sound due to being in a closed small room.. Its normal for that to happen for any amps i guess, but i do wonder how people setup their amps during live shows that is filled with loud crowds.. I've seen some live concert videos and albums where the band uses a full cabinet amp sets and played louder the noise im hearing in my room without these feedbacks..
It got me thinking to buy myself some noise gate effect so that i can beat the noise from outside and not getting feedbacks on the amp. I know that some bands uses it for getting their sound. And im aware that headphones will help to cut out the noise.. (p.s:- Im not much of a headphone guy.. I like my ears just the way they are. I do not wear any sort of accessories on my body except clothes and something to tie my hair)
Anyway, since i cant really buy the effectors, my brain started processing other method to get that sound.
I already know that my NUX FRONTLINE 30 is a pretty good amp in terms of sound with its built in effects but if i crank the volume to play for a jamm session, i'll get yelled at to turn it off.. (its a copy of a FENDER MUSTANG amp series i presume cause i saw one next to it when i bought it. Same function, size of speaker and power output. Except the fender is digital with extra prefixed settings, the nux is analog and slightly cheaper)
So i tried to find out what causes it. Is it my STAGG i300 pickups? Its working fine so far.. Is it in the gain settings too high?  I guess it is... Works well in low volume. And sounds awesome too.. But seriously? Playing on low volume on a 10 inch speaker? Cant we at lease have it halfway up? Cause that is such a waste of equiptment...
All i want was to eliminate that feedback when i turn up the knob. I looked around the net to find a solution without having to purchase a new gadget effects or a new amp but none suggested it. Though they do say that i should just use a headphone for high volume play.. (and burst my ears? Hell no)
So i sit back and wondered why it made a difference having a high volume on headphones.. I concluded that the noise from the phones didnt bounce back to the pickups..just like a mic on a normal speaker, so there will be no feedback sound.
I've tested the phone output to another speaker to see the results and it actually works.. But the second speaker needs to have some EQ on them atlease a bass and treble knobs. Otherwise, its just the same.
I tested that method over a few type speakers such as, a home theater speaker sets.. A cheap karaoke speaker peice (just one side), and my desktop pc speaker. And guess what? This method is actually a half set cabinet settings! Hah! So its legit to try out..
Now, i can crank up that volume to halfway up with high gain on the guitar amp. The output sound i got from the second speaker just wows me.. Except for the pc speakers.. Cause i think the power coming from the amp kills the output that the speaker can take.. In which the karaoke set that has an EQ built on it makes me able to get the tone that i want from my guitar. Without getting me a EQ effect. So note to self:- make sure the output can stand the input power capacity.
I figured that if i only play in my room, then this will do..
But if my buddies invite me for a jamm session in a studio nearby, i think i'll carry my Nux amp with me and test this method to a bigger amp sets..
lol..
Sounds kinda stupid bringing in your own amp to a place where you can rent them for a few hours.. I mean, guitars, i can understand.. But a cheap amplifier?
Yeah.. But dont get me wrong.. I felt that sometimes when you got too used to a certain setup, you lost your way using another. Get it? Its like when you've been playing a standard drum set all your years and you're good at it. But when you got to a gig that uses a full percussion set drums, i bet you only hit the things you know whats for.. And leave the rest hanging.. Right?
Yeah, i bet you do..
Hmm.. A Half Set Cabinet Of My Own.. I get it now.. Took awhile, but i get it.. I'll see what i can come up with it soon..