Funny and I thought I was .the only one that had that problem. That’s the main reason I avoid going to deep. Exhaling all the air from your lungs can be a real issue. I have found that I really need to exagerate the process. I exhale and exhale until I feel I can’t exhale anymore then exhale some more. Like you once I drop then I seem to be fine. But if I’m over weighted then I have problems staying neutrally bouyant. If I start to rise then I shoot up..lol.. so hard to do the safety stop. I’m working on it and seem to be able to decend a little easier now but ...safety stops... yuck.. sometimes I wonder if I’ll ever master those. I live less then a hour from a local quarry and keep going there to practice practice practice... I love diving :) good luck. I’m sure we’ll both get it hopefully sometime soon. :)