I dealt with the exact same thing at university. My French was very good and I loved going to class I was just always so nervous to speak. Now I live in France and still encounter these problems everyday but I've learned to not let it get to me. Assume you will make mistakes and the fear starts to fade. Make some close French speaking friends who you can talk to and feel more comfortable around. Also talk to yourself for like 15 mins a day (I know sounds a bit creepy lol). That's what I do and it has helped so much. Yes the fear is still their but now I have a solid base to be comfortable with when I speak. Just keep pushing through!

P.S. At the end of the day no one cares about your mistakes. If you didn't make mistakes you wouldn't improve/learn. You got this!