New member can't get lucid

Thanks in advance for any and all advice. I’m new at this but a year has gone by and I’ve only had four dreams where I realized I was dreaming. The first time I woke up immediately with my heart beating fast. Second time I looked at my hands and rubbed them together. For about a minute I looked around at my surroundings and tried to make them vivid. It was “different” but still dreamlike and not clear. Once again I woke up. The third time I was driving a vehicle at night in my dream. I stopped the vehicle, stepped outside and started to spin around with my eyes closed. Each time I opened my eyes I was still there with not much visual clarity. This time I fell back into the dream. The last time, last night, I was very excited because it had been several months since my last opportunity. I put some stuff I was carrying down and started rubbing my hands excitedly and looking at them. They looked somewhat purple and the veins were exaggerated, didn’t look real. I was hyped up and giving it everything I had as I rubbed them together and examined them. I heard a noise in the distance and realized it was a beating heart. MY beating heart. Even then I was able to hang on another ten seconds before waking up. All of these semi-lucid (?) dreams had a quality that was slightly more than dreamlike but way short of vivid. I am getting frustrated. My opportunities don’t happen very often and I can’t capitalize on them. I thought that once I started recognizing I was dreaming that the second part would be easy. What am I doing wrong?

Yeah, unfortunately, becoming lucid is just the first step - but a big step, so well done on that! It’s difficult to give any solid advice without knowing which techniques you are using.
First thing that is apparent - you get too excited. You probably know that you need to be able to control your excitement in order to stay in the dream (that is not to wake up). Another thing that helps to maintain your lucidity (that is from losing awareness but staying in the dream) is by having a clear goal. When you have a goal it is harder to be distracted by things that happen in a dream. If you don’t have a goal then your mind can be all over the place and it’s quite easy to lose yourself again.
Usually as you have more and more LDs you learn to control your emotions, so I guess you should just keep going. I think most of us were struggling with the same problems in our 4th lucid dream. Then again, even with practice some dreams are more vivid and easier to control than others.
Are you keeping a dream journal? It might be the case that the dreams were vivid, and the memory just faded, but I guess if you woke up immediately due to excitement it is unlikely… You could try increasing vividness by stating your intention to the dream - just say “the dream is as vivid as real life and I am perfectly lucid”. This usually works for me. Be careful with the wording though, once I said “amazingly lucid” (rough translation from my native tongue) and i simply experienced lucidity “amazingly” - that is, it was an intense emotion rather than improved awareness, lol.
What did you mean by saying that your opportunities don’t happen very often? That you rarely have lucid dreams in general, or that you can’t engage in active practice due to life style/ other variables in your life too often?

Thanks DeskRaven. Yes, I am getting too excited. Next time I will try to be less emotional and more detached. I do keep a dream journal and able to recall at least one dream almost every night. I’m going to try shouting “increase lucidity!” next time in addition to rubbing my hands. I said my opportunities don’t happen very often because I’ve been trying for a year and only had four lucid events.