Question: So I've been looking all over the internet for a Decimal to Binary converter but all I've been able to find are Binary to Decimal converters, and Decimal to BCD circuits, does anyone have one?

Answer: 
As has been pointed out in other answers, you can use the venerable (and I do mean venerable) 74184. Of course, those things have been obsolete for decades, so finding them is .... interesting. If you go on eBay, you can get 20 year old Russian knockoffs for a couple of bucks apiece. You'll need 6 for converting 0 to 255. You'll also need some extra protection logic, since with a 3-digit input there is always the chance that you will inadvertently try to enter a number in excess of 255, and the results of that will not be pretty.

Then, of course, your 6 ICs will draw (worst case) as much as 100 mA each, so you're looking at 600 mA.

Overall, in terms of circuit board size, power dissipation and error resistance, you're much better off programming a 4k x 8 PROM such as a 2732. This comes in a 28 pin DIP, and they are readily available and easily programmed.
For a complete 3 digits BCD to binary converter you need 10 output bits for numbers from 0 to 999. 8 bits are good for numbers from 0 to 255. 

There was a TTL chip for that purpose, the SN74184A, see this [PDF](http://pdf.datasheetcatalog.com/datasheets/400/220358_DS.pdf) or that [PDF](https://www.utm.edu/staff/leeb/DM74185.pdf) datasheet. On page 6 or 3-736 there is a cascaded circuit using 6 chips for 3 BCD digits input and 10 binary output bits. 

If you can't buy the SN74184A, you may program its function table (page 2 or 3-732) into a PROM with 5 inputs and 5 outputs. Of course you may use a PROM with 8 inputs and 8 outputs too. Or you do a single chip solution using a PROM with 12 inputs and 10 outputs. 16 outputs may be used also, just don't use 6 outputs. Or 2 EPROMs with 4096 bytes of 8 bits. Larger EPROMs may be used too.  

The least significant bit of the lowest BCD digit needs no processing, therefore a PROM with 11 inputs and 9 outputs will do it too.