Advice I have to adopt my bothers

Fan question

I have to adopt my two bothers , I just had a baby and I have a 2 year old . I’m only 22 years old I only planned on having two kids , I’m getting my tubes removed very soon . I’ve been taking care of my brothers who are 4 and 6 on and off for about 2 years now . We have the same dad but different moms . Their mother had recently gone back to jail and this time Cys won’t be giving her the kids back , it’s either I take them forever or they go to a foster care . I have been taking care of them but I just not sure what to do , I literally take care of the four kids a lot just by myself , my boyfriend and baby dad works a lot and will help with his kids sometimes , would I really be able to handle this ? I love them and I probably will do it , but I don’t wanna get over my head and become overwhelmed ? Because this is a lifelong commitment?