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: 
Yes, you'll struggle to find one. The reason for this is that there is no common reason for a BCD to binary converter. Where do the BCD digits come from that you need to convert?

The purpose of the many binary to BCD converter ICs that are around are to support 7-segment displays in the pre-cheap-microcontroller era. You used to use a binary to BCD converter to break out each digit from your ADC or counter, then you would use a BCD to 7-segment driver to run each LED/LCD/VFD display to provide a human readable display of the binary measurement. As you can imagine, this was a rather common function in electronics devices, hence why the chips are readily available.

Without knowing much more about the problem you are trying to solve, your best bet is to use a cheap microcontroller. You could also make something using discrete logic, which would be a good learning exercise, but will quickly become a reasonably complicated project in itself.
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.