Can I do it?

I've always wanted to travel and arranged to graduate 6 months early so I could spend 4 months in Colombia. Everything has worked out and I'm about to buy my plane ticket, but I'm starting to have second thoughts. What if I hate it? Or I'm not cut out for solo travel? Has anyone else felt like this?

Yes. Everyone that has ever travelled has felt exactly like this.

I normally get apprehensive about the time of booking, thinking of all the things that I need to do, and unsure of how it will all be when I'm there (especially when I went to Zimbabwe this year and there was so little information available about the country). Then I calm down and enjoy the planning/organising. And then a couple of weeks before the trip it dawns on me when I'm doing and I feel the same way again. 2 days after you arrive it will all seem very normal, you will be adjusted to the country, you will have met people, and you will wonder why you were so worried in the first place.

Indeed, it's normal, everyone goes through that, especially before the first big trip, but it happens again for later trips (though the more you travel the less it happens). You may take a while to get adjusted, it may be a couple days, it may be a couple weeks but you will adjust and it'll be great. And if you find that you are not cut out for it, then there's always the option of going home early. Nothing wrong with that. Travel is supposed to be fun so if it's not, don't force it. Just give yourself a bit of time before deciding that you definitely want to go home.
You may also find that after a few weeks you have a slump, that's also normal. Just get somewhere nice and relax for a while, spend a few days just chilling, reading, hanging out in cafes... And you'll recharge the batteries.

Yes. Everyone that has ever travelled has felt exactly like this.

I normally get apprehensive about the time of booking, thinking of all the things that I need to do, and unsure of how it will all be when I'm there (especially when I went to Zimbabwe this year and there was so little information available about the country). Then I calm down and enjoy the planning/organising. And then a couple of weeks before the trip it dawns on me when I'm doing and I feel the same way again. 2 days after you arrive it will all seem very normal, you will be adjusted to the country, you will have met people, and you will wonder why you were so worried in the first place.

Spot on! @julie_l
I went through exactly the same thing before going on trips and things work out for me most of the time.
Adjusting my mentality and having faith in my decision is really important. It's really how you look at it.