You can do it - you ARE doing it!
Not sure how to answer your question about my partner as not sure exactly what you mean by struggling, iyswim. My partner does/has struggled too, I mean it;s a huge adjustment for everyone, especially when you have a baby as difficult as mine with hours of endless screaming for months on end 
. But it has never affected him as much as he only had 3 weeks paternity leave and then obviously he was away at work away from it all so he had more patience and could cope better with all the screaming when he was back as he lots of peaceful hours away from it! He sometimes says that when she's really bad and screaming loads, it's actually me and my reactions to it that make him feel more stressed than just her crying, but I don't think that's fair because if he had to deal with it day in day out all day every day like I do with no breaks then I think he would react more like me . But he is great honestly, super hands-on, he adores DD and always has. He does get super stressed and exasperated with her constant crying sometimes too but not as much as me, given he has more peace from it. He is really supportive of me and always tells me I'm doing an amazing job ad infinitum and supports me in getting the help and support I need. In the first few months there were a few occasions when he would call or text my mum and ask her to come over when I was struggling and bawling down the phone but refusing to contact her (my mum has been a great help, she lives a few mins walk away and doesn't work).
For me, most my struggles were related to specific things, like the birth itself and my physical and mental recovery from that; breastfeeding difficulties; DD crying all the time. It has all been slow processes but just gettting on the right paths to deal with those things has helped me feel more in-control. Stopping BF helped me a lot. Not instantly, as I was then wracked with guilt and really upset about not being able to successffuly breastfeed, but I gradually weaned her onto formula between week 6 and 12 and the more bottles I introduced the easier it was for me and then after I completely stopped I had a few weeks where I felt awful about it but once I'd gotten over that I saw how much better I felt from it and I wish I had just done it much sooner. Also finding a really good, supportive GP, and my new HV is great too so I know I'm being supported and I can contact either of them if I need help. And accepting lots of help and support from DM. Getting out every day helped me too but I didn't routinely manage til she was about 4 months old and even then often it was just for a walk, or just to DMs and sit about in her house all day 
. We are much more active now, going for more walks, playgroups in churches and childrens' centres, go to the library, I met some parents through the app Mush who I sometimes meet up with in the play café for coffee etc. I would recommend Mush, The Wonder Weeks, and Hoop for apps for your phone btw. I also don't drive but where I live there is loads of stuff within walking distance to take DD to, I couldn't take advantage of them earlier due to anxiety (pre-existing) and the added problem of DD crying all the time, but now she's much better when out so jsut starting to explore more of the stuff going on. I do get the bus with her sometimes though, into town for the baby cinema, or to one of the childrens centres for the baby group. The first time I had to get the bus I went with DH as a practice to and from town 
. I was very anxious the first time on my own, and the first time I had to get an unknown bus route on my own to the children's centre, but it was always fine and I've never had any problems. I do have quite a light, small-ish pushchair tho (Cosatto Wow).