sex help :(

So I've been having sex since may and I love it. But sometimes when we are in doggy style or anytime where he's hitting it from behind it kinda hurts me :( it just is uncomfortable and that makes me sad bc everyone says that doggy style is the best but it just doesn't feel that good for me because it hurts. Also, he likes when I'm on top and I like it too but I get really worn out easily by being on top and I don't know what to do about that! :( I don't want to just have missionary sex every time I just want doggy to feel good and to not get so mf worn out when I'm on top. Help