This is so hard

I am having such a hard time. I love Jon, but I think I'm going insane. He needs to be held literally all the time, and he usually won't sleep at night unless it's with us. This poses a problem for me because I hate the idea of co-sleeping and I can't sleep when he's in the bed anyway because every noise he makes wakes me up. He also eats way too much, I think, and he's growing ridiculously fast. He's so fussy all the time too. Twenty-four hours a day of this, and it's no wonder I'm frustrated. But Steve is angry with me for being frustrated. We've been fighting so much, and that is not helping my mental state right now. I really don't know what to do. I am starting to think I have some form of PPD because I am unhappy all the time, I cry at least once a day, and sometimes I really just want to run away and not deal with any of this. I know other babies go through the same things, and everyone keeps saying it will get better, but it is only getting worse right now. I can't take it anymore, and I really think I'm losing my mind. I am going to go to a mom's support group, and I've also joined a mommy meetup group, but I don't know if this is going to solve my problems. I think as long as Jon is being difficult, I am going to continue feeling this way. And it's even more depressing to know that it is killing our marriage. Steve just doesn't understand, and I know it must be super frustrating for him to deal with me being like this. But he keeps telling me I just have to suck it up and deal with it, which may be true but that is not the type of thing you say to someone who is going through some sort of depression. I take good care of Jon, but at the same time I am so miserable all the time. I just don't know what to do. So tomorrow (assuming I get some sleep tonight) I am going up to my in-laws' house. It's a 4-hour drive without stopping, so I'm thinking it might take me about 5 hours since I will have to stop to feed Jon. But at least there I will be around people other than just the baby all day, and my MIL will be able to help me out with him. Plus Steve and I will get a break from each other, which sadly is much needed right now. I just hope things improve soon, because I don't know what to do anymore. I just have to get through this week, and then I will talk to my ob/gyn about possible PPD at my appointment next week.