This is a very complex question and solutions depend on your inter-personal chemistry, personal ambitions, sources of motivation etc.
Picking up on your saying that you lose energy on "random/jam/noisy" moments, try concentrating your efforts on simple, mutually agreed-upon ideas that you can make to work, but that are still enjoyable by everyone. All of you should have a clear idea on what the most essential musical idea is for each song, and what each player's role is in that idea. And then try to execute that idea as clearly and effectively as possible. Keep it simple. If things get random or noisy, it might mean a lack of control, or lack of a central idea, or not committing to the idea.
It's possible that some of you lack the needed technical ability to succesfully perform something that you're trying to do. Then you'll have to slow down, leave out something, do something simpler. Only play things that you can actually make to work.
Rhythm and harmony need coordination between players, so that everybody is playing the same idea, not multiple conflicting ideas.
What is the rhythm? Can you "hum" the essential thing about the accompaniment's rhythm? Agree and coordinate simple ideas for the following "instrument axis". (If you can't agree on these, you need an arranger person or other kind of "boss" to plan and dictate it.)
- Kick+snare <--> Bass. Does the bass mute when the snare hits, or does it play on both kick and snare hits? Does the bass and the kick drum play in unison?
- Hi-hat+Snare <--> Guitar. Does the guitar play the same hits as the hi-hat, or the same as the snare? Or both?
- Guitar <--> Bass. Should they play the same rhythm. At least the guitars shouldn't play very low notes that disagree with what the bass player is doing.
- Guitar 1 <--> Guitar 2. Do they play the same rhythm, or complementary rhythms? Are you sure they're playing the right chords and notes, and should they play in different positions (higher and lower on the neck) or the same position?
That said, every rock band should be able to enjoy jamming together, like a 12-bar blues or 8/16 bar loop. It's a sign of a healthy band. Keep a simple, enjoyable groove going. Everyone should contribute to the common rhythm, without messing around. Let each player have a turn playing a solo, but only one at a time. Creating and improvising stuff on the fly can be rewarding - but playing tightly together with other instruments is rewarding too. Let everyone have their moment doing some improvisation, but what comes to playing as a band, it's the tight playing that you should seek your gratification from.
If some of you can't get enough motivation and enjoyment from just playing tightly together, then try to figure out what the problem is. Is the playing not tight enough? Or is the rhythmic (or harmonic) idea too boring? Is the whole genre not enjoyable from someone's point of view? Then you'll have to do something about it. Write more interesting and more enjoyable ideas - but you'll have to stay within the limits of what you can actually do. There are people who just cannot commit to any predetermined musical idea, and want to mess around all the time, elbowing everyone else... but I hope that's not your problem. If it is, you'll have to somehow restrict or contain that sort of compulsive creativity so that it contributes something enjoyable and constructive, and doesn't destroy the simple musical ideas of each song.
