Hey brother, just got myself up to date with your log. I'm glad to see you giving this a solid go.
I've been lifting using the SS principles for 4 years now, and coaching for 2; not SSC but I've seen a lot of reps under the bar and had some success in my own lifting and with folks I've coached. Look at some of my articles on the website to get an idea (under author Geoff Bischoff, or in one instance, "George" Bischoff, because reasons), or look at my logs, if you want proof that I know a little bit about this stuff. Or just read on.
I'd like to address a few things I see in the log and in your videos.
0) Weight gain. This is the hard bit for skinny dudes. When I coached Tim, eating was like a second workout for him. For my part, I was a 71" 185-lb dude when I started, age 40. I did GOMAD. It's not recommended for guys our age, but it didn't kill me. Quite the contrary, I gained 40lbs the first year of training despite my advanced age, and added (for sets of 5) 130lbs to my squat (275 > 405), 70lbs to bench (245 > 315), 60lbs to press (145 > 205), 115lbs to deadlift (345 > 460). Tim did GOMAD also, as a 20-something, and added 30lbs to his bodyweight during LP, from 173 to 203 (he's 74" tall iirc), and got up to S/B/P/D 370/260/140/375 in half a year (might be off on the specifics; I put Tim in an article called "Tim gets strongish" and the data is better there since it's straight from logs). Consider drastic measures SHORT TERM for weight gain. Aesthetics for a newly single dude are important, got it. Strength is aesthetic.
1) Squat. The video at 135 is pretty good. Based on that performance, there's nothing that should be limiting you at 150. If over time you can get the bar a half inch lower on your back, that is to be preferred. If you work to get your butt back and upper body bent over earlier in the rep, that will serve you well, too. Here's where I'm concerned:
You say 150 across is near failure. The only way I know of to measure that on myself is with video. The reps north of 405 for me all feel heavy AF, so I film them. If it takes me 3 seconds or less to get from bottom-of-the-hole to lockout, I'm not "near failure." Your sets at 135 took not longer than 1.9 seconds (longest rep) with an average of about 1.6 seconds per rep. A roughly 10% increase to 150 probably hasn't changed that much (though I'd love to see film). The heaviness is likely more in your head than in your movement pattern.
If it really is "near failure" then put in some mods but KEEP ADDING WEIGHT TO THE BAR. Absolutely positively don't stand still. Add to the bar.
Mods include: Light Wednesday (M: 155x5x3; W: 120x5x2; F: 160x5x3) for example. Or Top-and-drop (M: 155x5, 135x5x2; W: 160x5, 140x5x2; F: 165x5; 140 or 145x5x2; stay close to 10%-20%-ish offset). Eventually, both at once (M: 155x5, 135x5x2; W: 120x5x2; F: 160x5, 140x5x2). Ideally: Only introduce one mod at a time, and carry it for as long as you can before adding an additional mod. But add weight not less than twice a week, and ideally 3/week. Microloading squats (2.5lb jumps) is for female lifters, or very small or old male lifters. You ain't that small or old bruh.
2) Bench. Get your elbows and lockout under control. Lockout: Should be directly over the glenohumeral joint. Yours (in the filmed sets at 140) is slightly forward of that (closer to your feet) which creates an unnecessary moment arm in the rep ... which makes it harder than it has to be ... which ultimately causes you to be able to lift less weight, and makes the bench feel heavier than it is. Elbows: Your filmed set shows a side-view. In the side-view, at the bottom of the rep, where the bar touches your chest, your elbows are behind (closer to your face) the barbell. Those elbows should be in front of the bar all the way down (nice strong tuck, 45-ish degrees depending on anthropometry), so that you naturally bench the bar "up and back" to lockout above the GH joint. Fix those two things and you won't have as much trouble benching. Your shoulders will also thank you. Also: Microloads on bench press ARE for men.
Add weight every session. Mod like the squat if you have to: Top-and-drop, light-day-Wednesday. But you should have a new load on the bar every time you approach it to bench.
3) Press. No film; but the numbers look right. I see you microloaded to 87.5 recently. Good on you. Keep creeping it up. Don't be scared to mod (same protocols), but don't do it too soon, either. For male lifters, I like to hit failure on a set of 5, and then that day, transition to triples (Only got 3 reps? Okay, do four more sets of 3). That's not the orthodox advice, but it's worked okay for me with male military lifters so far. The orthodox advice I believe is "When you THINK you'll fail your next set of 5, transition to triples." Problem is Army dudes never "think" they're going to fail a set of 5. But first mod: Switch to triples across when appropriate.
4) Deadlift. Set your back A LOT HARDER. 220x5 looks good. Don't put the bar down so slowly man! Save your energy for the upstroke. Let the downstroke be fast. Don't drop it (keep control of the bar with your hands) but let gravity do the heavy lifting there. On programming: If you're due for a volume reduction on deadlifts, step one is to scale back to 2 pulls/week. In that midweek spot you can put power cleans, but you can also (shhhhhhhh) put nothing. Like, just don't pull that day. You won't explode. You can also put in light deadlifts for form practice. For it to be meaningful, it can't be stupidly light. If 250x5 and 255x5 are your progression pulls for the week, maybe knock 10% off for a pair of triples midweek: 225x3x2 and practice squeezing the hell out of your back.
But keep adding weight to these, as well. First time you hit a set of 5 deadlifts where you're like "Whelp, today's set came up but next set definitely ain't," switch to paired triples and drive on awhile. So like 260x5 on Friday comes up but feels like warm death? Okay, Monday come back and hit 265x3x2.
If you **eat the food**, you've got at least another month of LP in you, with plenty of load additions for all four lifts.
Looking forward to seeing the 38-year-old version of you crush the younger version of you into protoplasmic goo.