I don't want the receiver to see the other people I am sending the sms to

In order to send group text message so the replies will be sent only to you as the sender, please open your native Settings application, choose Messages section and disable the following:
iMessage - OFF.
Group Messaging - OFF.

In case your recipients are in GREEN color you can keep your iMessage service on.
In any case, you can turn iMessage on after you send the message.