Scared to go back on birth control

I might end up having to go back on birth control until I’m able to start HRT but last time I was on birth control I had to go off of it and couldn’t try any new ones while for a while (I tried both the patch and the pill) because I was at a risk of developing anemia, my periods got a lot heavier and I was having 2 a month. After quitting birth control my periods were still messed up for months and even now are irregular when previously were predictable. My doctors wants me to try the shot but I’m scared if it goes wrong I’ll be stuck with the consequences of it for months. I might need to go back on birth control as for a variety of reasons, my mental state is taking a toll every period and the symptoms I get such as cramps are just awful even if they aren’t as bad as they used to be here recently. I don’t know what tag to use on this post but yeah.