Get Toby neutered, then take him to a shelter for speed dates to see who he gets along with best so he essentially picks his perfect match. If you get another young bunny (make sure it’s at least 8 weeks old this time and from a reputable breeder) you’ll have to keep them separate until the second one is either spayed/neutered. So if you get a second one it really is best to let Toby choose for himself if possible.
Also, you’ll need a contingent plan for if they can’t bond. Do you have the time, money, and space required for another single bunny. You’ll also need to think about these things while you’re bonding them because they need to be 100% separate at all times unless you’re doing a bonding session. Remember that Toby has been a single bun since he was 3 weeks old, so he could potentially be very territorial towards a new bunny. They probably won’t instantly click. Bonding takes a lot of time and patience. Some bunnies can take up to a year to bond and others take 2 weeks.
And lastly, remember a new bunny could have a very different personality than Toby. From what I’ve seen on insta, Toby is a big loveable sweetheart, and it helps you’ve had him basically all his life. If you end up with a shelter bunny, be mindful that you don’t know much about their background. They could be very shy and timid and not enjoy being pet due to abuse or whatever else in the past. Even if you do get another breeder bunny, they could also be very different. Toby was too young to really be scared of a new environment. He thought of you as that mother figure. A bunny that’s already 8 weeks old and older might take some time to warm up to you. Just continue to be as patient as possible. 