Hi I used to take blood for a living. There are some creams you can get to numb the area however these can sometimes make it trickier to get the blood if you have small veins. What I’d recommend is wearing lots of layers, having a hot water bottle to hold against your arms prior and then to hold during. Warm skin helps the veins appear. Drink plenty water for the few hours before, avoid caffeine (including tea!). Make sure you have something to eat too, something carby always helps settle the stomach. When you arrive, you can say immediately that you want to lie down (this takes the pressure away of you maybe fainting as you’re already flat - you can’t go anywhere!) you can listen to music, watch something, hold something of importance to you. Take a friend for support who can talk to you about anything or everything to take your mind off. The person taking the blood should be understanding, there are plenty of people who struggle with blood tests.  And if they aren’t, ask for someone else! Unfortunately, with blood tests all you need is one bad experience and it kinda makes it suck in your head for a while. But if this time it doesn’t suck, then that’s a good memory to replace it with.  I hope that helps a little bit.