Those two thing I said above are a couple of things I can say you may do right away without having to change your skill level.
If the trouble is mostly from service return, then obviously with time one must learn to read the ball better and be ready to receive with different options, short bump, half long bump, fast long bump, dead flip, spin flip. Improving those takes time and learning. I myself am still learning and it is taking more time 'cause I can't practice or even play much until I drive 6 hours. I feel ya.
Also keep in mind, any of the stuff you do manage to improve upon in practice will take MONTHS to show itself in more points won in a real match.
On defense, if you block and want to be more aggressive, take the ball early and go through the ball a little more to create a faster block. You can also take it later and push through the ball with your block to make a counterattack, even if it isn't heavy topspin, it is still a quicker shot than a block and when you learn to pplace it better, that is one nice offensive shot.
Sometimes, just pushing the ball and allowing opponent to attack is a good thing. Why? if you are able to place the ball where you want it, hopefully where opponent will get there off balance off time, you create more misses and you have less work, less risk. or you push the ball where opponent moves a little and can still attack. You get better at reading opponent and you are parked there ready to block ball where he isn't and watch him watch the ball go by him or scramble for it in futility. Then you get to snicker like Muttley as the you get another point added to your score. You are controlling when and how he attacks and have a good chance to be there on first attack to control the point. Blocking is still offense, even if it involves using a few blocks to move opponent to where you want them for you to finish or opponent to miss and smash his bat like John McEnroe.
Defense isn't a whimp's play if you have a plan of attack, it can be very aggressive, especially our punch blocks when opponent unwisely chooses to attack with too much pace or leaves heavy spin ball too high.