How to set boundaries without ruining a friendship

For context my friend and I are both females in our early 30s. She’s sweet, a great conversationalist, and gives good advice. Sometimes I also have to work with her for little projects we do in our community. However she has a habit of talking a lot and being a bit of a control freak when we plan things. I’m more the type who wants to come in, gets whatever we need done, and leave. She says she wants to respect my time, but she always tries to hang on when she senses I want to end the call by talking even more, faster and with more vigor. However when she has to leave the call she isn’t afraid to vocalize it.

Our calls often last over 3 hours when I only want it to be 2 at most. I know it’s partly my fault — I should be better at vocalizing my limits, but it feels really awkward for me to do so. I guess I’m afraid of coming across like I don’t care about what she has to say and hurt her feelings. I myself feel taken aback when others end our conversations too directly or abruptly, and I don’t want to make others feel that way.

But I also know I need better boundaries. That’s where a lot of my frustration lies. I want to be a bit more bold with it but have difficulty finding it in me to do so because it may hurt the relationship. I actually have tried being more firm (but never rude) when asking for what I want or saying no at work, but it’s upset people before and also jeopardized my job (for example, I got criticized for pushing back for refusing to take on extra work.) and I think part of me is operating off that fear, that I might offend whomever I’m conversing with.

Any advice?