Yes, a sling/wrap for during the day. My daughter had all her naps in one until she was about 8 months old, and was constantly in one or held at only 4 weeks. We managed to put her down in the moses basket once for 20 minutes and that was it. Otherwise, she had to be held or worn or in bed with us.
If you want advice on just getting through the nights until it gets easier, I would recommend doing the nights in shifts. This is what we did up to about 8 weeks. I did a feed around 7pm, then I took a shower and went to sleep. My husband brought our daughter to me when she woke for a feed next, usually around 10 or 11pm, then he took her back until about 1am. He'd let her sleep on his chest or in the wrap while he watched tv. I got a few hours of sleep. Then we switched off and I took her for the rest of the night until morning, sitting in the chair rocking her or holding her in bed
(while awake). We planned to co-sleep but she wouldn't even sleep in bed with me at that point. She had to be on me. So that's what we did. Anyone can cope with 5 hours of sleep a night for a short period of time (yes, even dads!). But it's a lot harder when only one of you is getting no sleep at all. It's a really hard phase, but it will pass. At 8 weeks, some nights she started to sleep all night in the co-sleeping cot next to me from her last feed at 10pm until the morning. It was amazing to sleep again! It won't be forever. You won't create bad habits. The point is the first couple months are the hardest thing ever. You need to get sleep and you need to do it any way you can. You can eat crappy frozen dinners for a week so you don't have to cook or do much cleaning up, so you can get yourself to bed early. You can go without seeing your partner much if you need to take yourself to bed. And bonus, your partner gets lots of daddy bonding time, which was wonderful for my daughter and my husband. And it's very short-lived.