Do I have to get braces again? Had to get them to make space for a missing tooth I was born with. Apparently the space isnt big enough for the implant

Possibly. Hard to say without seeing you but that is a method of treatment in order to make the space large enough for an implant. You might want to talk to your dentist about other methods of filling in the space. Sometimes a space can be closed just using restorative materials.
Probably. Either not enough space created the first time, or retention insufficient to maintain space. If rx was done by an orthodontist, go back for a re-evaluation. If rx was done by a gp, bit e the bullet and see an orthodontist.