Big fan of Danbury animal welfare society (DAWS.org).

It’s a really decent option and small is efficient…..

As people said, get that thing inspected and cleaned! The temperature difference comment is legit but I’d be surprised if thats your issue this time of year. Either way (after you get the thing inspected), make a torch by tightly rolling up a big piece of newspaper then light it, hold it up towards the top (by the open flue) to get hot air moving up), then light crumbled newspaper sitting on top of the wood, then light newspaper on the sides of the pile of wood and then light under the wood…… also, make sure you get seasoned wood. A lot of places will sell you crap wood that won’t burn easily and will create a lot of smoke