Need some advice Ive currently got really bad back pain as I got an epidural with my first kid and…

Need some advice Ive currently got really bad back pain as I got an epidural with my first kid and now constantly have pain but its much stronger now that im pregnant any ideas on what i can use. I checked on google about heat pads and it said only if it was an electric one so i can control the heat but when i searched about hot water bottles it said i could use any heat pad or a hot water bottle in a towel? Opinions please 🤔🤔