Looks like you ran out of real estate in that small pot.
First off, never, ever, ever transplant. Ever. That's shit a nursery does, not a person growing only a couple plants. Put the germinated seed in the final pot you're growing in.
Secondly, it's not THAT bad. Yeah, you sort of bound it up and starved it out a bit. But it really doesn't look that bad. Just keep on keeping on in the larger pot.
In the future, never, ever, ever transplant. Nurseries do that because they're germinating 100 plants at a time. So for them it's more economical space wise to use smaller pots that take up less space. As the plant grows, they're harvesting a grow of big plants, moving medium plants into that space, transplanting small plants to the medium space, and so on.
But for anybody just growing a few plants at one time start to finish, there is no reason on this earth to ever transplant you grow. All it does is put you at risk for shit like this, and you risk stunting the plant each time you transplant it if anything goes wrong.
Hang in there. You'll be fine.