Frustrated, Need Mid-High Master, GM Please Help!!

For reference, if a professional is playing completely passive and droning as hard as they can, they can hit up to ~60 drones and ~75 supply at the 8min mark, so you're not that far off. The difference comes from refined openings and sharp mechanics but again, you're pretty close and this is good.

Engagements are absolutely important to Zerg and especially if you're going mass unit heavy (e.g. roach/ling). In most cases your engagements were good, but be sure to always try to setup flanks and engage from as many directions as possible to give yourself the best chance. It's easy to forget this, especially if you're caught off-guard, but it's easily one of the best ways to play better. The catch though is that you cannot forget to macro. I'd suggest you try and sent a unit out to see where your opponent is moving out to, pick a favorable location to engage, split your forces up to converge on it, go back to macro right before the attack, and then attack and spend larva and inject during the battle.

As I can see while going through your replays, you did not succumb to negativity and were in good spirits even when you lost. This is probably one of the most important assets you can have. Now you just need a way to channel that positive energy to fuel your growth.

Roaches and zerglings are generally considered "massing units" as in you need a lot of them for them to be effective. This means several things: it emphasizes mechanics since injects absolutely cannot be missed since these units are so larva expensive, engagements must be taken carefully as losing a lot at once means you cannot replace them quickly enough, upgrades become very valuable since they can apply to so many units, and you need a certain amount of them to have a "critical mass" to be able to do something with them (which usually means your opponents needs AoE to counter that critical mass or lose). So in this manner injects become absolutely critical and macro hatch timings become very important to consider so you can maintain your army.

ZvP is very timing dependent, more so than in the other match-ups since it's not always possible to keep constant tabs on your opponent via attacking and there are so many timings that Protoss can do to Zerg. Among professionals there are varying styles (some scout more than others), but the common thread is that they always check for the gas timings at the natural. You're basically looking for the gases to be taken at 6:00. If the Protoss takes both, assume tech. If only one is taken, then it's a possible immortal/sentry. If neither are taken by 6:30 then you need to put your roach warren immediately in response as a gateway timing (either a poke with a +1 4gate or some variation OR a 7/8gate all-in). I'd further recommend that you sac an OL into his main at around 6:45 or 7 to get a scout on his tech. It's always a good idea to send your first 2 OLs in to scout the gas at the natural and one near the main to sac. You can do this even on 4 player maps, but it requires you to send them out in the correct positions first so you can rearrange them into position depending on the spawns. Note that if you do this you can't spot your natural for cannon rushes, but you can still stop them (but I won't be going over them here). These timings aren't fool-proof (there are builds that Protoss can do to fake gases at the natural, etc.) but they will get you started. Remember that you have the better economy so you want to see what the Protoss is doing, then react to it and maintain your economic edge.

As a general principle in all Zerg match-ups, if you're not getting melee/carapace upgrades and infestors, you're delaying your late-game transition and going for a huge mid-game attack/all-in. Now there's nothing wrong with doing this, but you absolutely need to be aware of the fact. What many professionals will do in ZvP is to go roach/ling to hold off mid-game timings and try to pressure the Protoss before they secure a 3rd. Once they see that the Protoss has successfully secured their 3rd (sim city is going up, they have the necessary unit composition defending it) they immediately thrown down a second evo and infestation pit, take a 4th, start upgrades, tech to hive while stopping roach production and poke around as much as they can with the army they have. If you do decide to go for a mass roach composition then you're essentially on the clock, trying to do as much permanent damage as possible (e.g. kill their sentries and non-gateway units, expansions, mining, tech, etc.) before they secure their 3rd and get out the army composition necessary to beat mass roaches (usually something like stalker/sentry/immortal/colossi).