"Buy a faster guitar!"
Just kidding, but I wanted to kick off my response by this recurring joke among guitarists, because I believe that the most common wrong idea about learning an instrument is that you have to buy more material, more equipment, and spend more money in general to get good. It is bullshit, as long as you don't buy truly bad equipment (like the absolute cheapest option on the market), you are good with what you have. It is your own skills you need to develop, and to do that you need time and not money, but most importantly you need quality practice time.
So as a long-time guitar player and occasional teacher, my first suggestion is to honestly observe and assess your own way of practicing: are you practicing mindfully or are you going through the motions? To clarify, to practice mindfully means to try your best to "listen" to yourself, not only with your ears but also with your fingers and rest of the body, and to be critical of your playing, not in sense of self-blaming, but questioning if there's a better way to do something and being willing to change how you do it. By converse "going through the motions" means to mindlessly repeat the same thing thousands of times thinking that one day all of a sudden it will work: the problem with that, is that you might repeat the same mistake a thousands times and get better at doing the same mistake instead of the right thing. Needless to say, practicing mindfully is a lot more efficient than going through the motions.
Second, specifically on finger independence. If you think this is one of your major problems right now, one of the best exercises is the good-old chromatic one-finger-per-fret drill, the "1-2-3-4" which is typically one of the first (if not the absolute first) technical exercise every guitarist is taught to do. I think you know how this works: you start on low E string with your four fingers on the first four frets and play 1-2-3-4 frets (index,middle,ring,pinky) on each string up to high E, then shift your hand one fret up and play 5-4-3-2 (pinky,ring,middle,index) downward from high E to low E, then keep shifting up one fret at a time.
However, there are a lot of common misconceptions about this exercise, so here I am going to tell you what I personally teach to others about this exercise...
1) This is not a warm-up. Do this exercise when you're already warmed up an "in the zone" for practicing.
2) Do not use the metronome, because the purpose of this exercise is not related to timing, and the metronome will force you to tense. It is instead a key purpose of the exercise to learn to relax all the fingers that are not currently playing a note i.e. when you're playing a note with the middle finger, try your best to relax the index, ring and pinky.
3) The 1-2-3-4 pattern (meaning I-M-R-P in terms of fingers) is actually the least important to practice, and yet most people only practice that one because it takes time (a few minutes) to go up all the frets and then maybe back down, so by the time the finished the exercise with I-M-R-P (and P-R-M-I when going from high E to low E strings) they are already bored and move to other exercises. But fingers independence develop when you practice other patterns! You have to try for example 1-3-2-4, 1-4-2-3, 1-4-3-2 and also starting with other fingers like 2-1-4-3, 3-1-2-4 (there should be 24 combinations if I remember). Don't worry, you don't have to practice all of them every time, it's good enough if on a given day you practice different ones from the previous day. I think it's best to set yourself the time you are willing to spend on this (even only 5 minutes is ok) rather than a fixed number of patterns.
Last, for finger stretching, this is something you need to be patient about, it might be frustrating to wait a long time but you should definitely avoid hurting yourself and maybe have the opposite results at the end. One fairly obvious way to develop this is to modify the previous chromatic exercise by adding a "fret gap" between two of your fingers. In terms of frets, it means to do the chromatic exercise by patterns such as 1-3-4-5 (gap between index and middle), 1-2-4-5 (gap between middle and ring -ouch!!) and 1-2-3-5 (gap between ring and pinky). However, don't try these immediately from fret 1, where the gap is largest... start somewhere on the fretboard where your fingers are still comfortable (could be for example 7-9-10-11) and then move downwards gradually.