That's good to hear that you managed to confirm that the purchases are a necessity, and that you can afford them. Perhaps you could try this as a way of easing your anxiousness.
1. Give yourself 15 minutes to write down all your worries about the purchase.
2. Stop exactly at 15 minutes, and start going through your list.
3. As you go through your list, start challenging each thought on the list. You can challenge them by confirming if there are any evidence that it is true or not true? What is the likelihood of what I'm thinking will occur? Will worrying about this help me, or hurt me? What would I say to a friend who has this worry?
4. As you challenge each thought, you can also start to think, whether each of your thought can be solved by you. If the problem can be solved, you can come up with a solution to help you with tackling this worry (and it doesn't have to be perfect). If the problem cannot be solved by you, you'll have to accept the uncertainty of the future, as we can't control a problem that cannot be solved.
It's okay to feel anxious about things, our mind loves to think of creative and unimaginable things that may or may not be real. I hope the above method can help you with coping with your anxiousness. Also, happy to listen to your worries if you'd like to chat about it with someone.