I can sort of understand the feeling bad when you see others with massive places...I remember feeling like that at times too. I'm a B6 RN with 2DC (mine are 20 and 13)...also living in a v small 3 bed semi (one normal size room and two box rooms upstairs, and a v small kitchen, bathroom and sitting room downstairs...no hallway!). I work FT and am a single parent. House is rented (I can't afford to buy). We live in the SE, and I've stayed in this area as I've worked in the same Trust for the best part of 3 decades, and for the DCs schooling (very good schools). My only sibling also lives close by (our parents are deceased, so good to have some family about). I'm the lowest earner in my family (out of siblings, uncles, aunts etc).
Most of my DCs friends have larger and more swanky places. Like I said, I used to get a bit down about things but then gave myself a talking to: this place is small, but I can afford it on my own. I can pay the utilities, there's food in the cupboards, I'm healthy enough to be able to work FT in a very acute setting. My small house can be kept warm in the winter. I can afford to treat the DC on occasions and I can take us away on holiday (luckily, we enjoy camping!). We have a lot more than many do.
Also....I remind myself that chose my career (initially one professional career in the NHS and then retraining as a nurse), no one forced me into it. Nearly 3 decades back when I was getting in to uni, perhaps COL etc meant an NHS FT wage went a bit further, but it was never going to be a massive money spinner. Would I have gone down this career path knowing what I know now? I don't know. I don't know where you work, but for us these days, if I work a bank shift at my hospital, I would get paid £15/hr gross (def not a B6 wage!)....and no doubt with expectation that I work as a B6!! I'm exploring other roles or additional things that I can do to increase my income - maybe bank/agency at other places, or events medicine/nursing.
I can promise you that the DC's friends aren't going to be fussed about the size of the house: I normally have a house full of kids visiting (some of DCs friends really do live in mansions!). Sleepovers are normally on the living room floor....or you can just about wedge a camping SIM on the floor in each DC's bedroom. In the summer, they can put a tent up in the garden and camp in there. We all just muck in really, budge up and make room for people. The people who matter aren't going to look down on you...and as for the ones who do? Well, sod them!
Focussing on other things though...WTF is going on with regard to your DH and his weaponised incompetence?! A paramedic not giving his own DC correct medication?! Sod the situ with the house, it sounds like there's more important things to address re: the imbalances with you/DH!