Sex Struggling

I’m currently on birth control on the depo shot I’ve been on it for almost a year now it’s so hard to have sex with my current partner I’ve been with for almost two years now he is a little on the thicker side but I’m always dry and In pain he thinks it’s his fault but it’s not in very sexually attracted to my partner we use water based lube as well and i still manage to get dry quickly. Any help?