I found with both my kiddos there were a few milestone points at which things seemed much better than before. One would definitely be around 3 months, when they get more interested in the world around them and more likely to be happy to be put down for a (short) while. And I agree with the other mamas that around 6 months is another time when things suddenly seem to shift into "life is easier" mode.
My first dd only napped in arms for the first 6 months of her life. I just went with it and ended up watching lots of TV series' on DVD (lol). When ds came along I already had dd to keep up with so sitting around watching TV with a babe in arms just wasn't gonna happen. He ended up taking almost all of his naps in the baby carrier (a mei tai was what worked best for us, but every babe/mama is different).
One piece of advice I would give is to try to get out of the house as much as possible. It doesn't seem like such a drag to have your baby napping in a carrier on you all the time if at the same time you're out walking, shopping, sitting in a cafe reading a book (if your babe will let you sit that is, lol), etc.
If your LO is very gassy/uncomfortable (and therefore fussy which probably leads to mama being exhausted and frazzled) you might want to consider either not supplementing with formula (perhaps giving expressed breastmilk in a bottle instead?), trying a new formula, and/or trying a different type of bottle (I've heard that Dr. Brown bottles are good for gassiness). I know that formula can be a lot harder on the wee digestive systems than bm. Having the break of giving one formula feeding might not be worth it if it leads to fussy/gassy babe.
Hang in there mama! There is light at the end of the tunnel - I promise!
ETA: I don't know if you're already co-sleeping, but if not you might want to give it a try. My dd slept in a basinette by the side of the bed and later in her crib which was in the same room as us. DS, on the other hand, has slept in the bed with us from day 1 and it has been SO much easier, and I've been able to get SO much more sleep and feel SO much more well-rested. Just rolling over onto my side to give him the boob, still lying there in my comfy bed is miles better than having to get out of bed, get baby, bring her to my bed to nurse her then carefully try to get her back in the basinette without waking her. I'm a big time convert to co-sleeping, lol!