I agree with some of the others that it sounds like the problem isn’t the reviews, but your ability to stay focused on your task. It sounds like you need to make yourself a study space and develop study patterns that let you get stuff done.
Some people study really well in a low distractions environment: an empty desk surrounded by silence (or noise reducing headphones or white noise app running) and nothing to do but the task in front of them. Other people find this environment even more distracting and would rather have music or TV running in the background or even might learn better getting jostled in the middle of a noisy train. Find out what works best for you.
A really common technique is to break down the task into time periods or amounts of work. Set a timer and do nothing else for that time period then take a short break. Suddenly want to look something up? Don’t switch tabs, keep a pencil and paper next to you to write down distractions and and get back to work. Look it up later. Need to go to the bathroom? It can wait until your break. Have a nosy roommate or parent or sibling poking in? Let them know ahead of time how you’re chunking your time and if they need you, you’ll be happy to help or speak during the break time. Don’t forget to set a timer for your break time as well as your work time. It’s really common to feel productive after a successful work period heading off to your first break…only to forget to return for more work.
The Pomodoro Technique is common, traditionally you set a timer for 25 minutes and concentrate only on your task for that time, then you have a 5 minute break. You can adjust the time period to whatever works for you. Starting small and increasing the work periods as you train your brain for focus is great if you can’t manage a long study period at first.
Find that you’re drifting off after just a few minutes? See that little clock symbol on the left that says “Wrap Up” when hovered over? That’ll limit your review session to 10 more reviews from the moment you click it. Finish those 10, then reward yourself. Set a timer for a minute or two, let your brain drift, use the restroom, watch a cat video, whatever, and when your timer goes off, do another 10 reviews. Rinse and repeat. Give yourself a longer break after several successful sessions and let your brain really relax. This can improve focus when you come back.
There are also apps for both iphone (Tsurukame) and android (Flaming Durtles). Plenty of people find it easier to do reviews throughout the day instead of dedicated study sessions. Do 5 reviews everytime you’re in the bathroom, a handful waiting for the bus or while being a passenger, some while waiting for dinner to finish cooking, 2 or 3 during every ad break on Youtube, etc. This can get a large number of reviews done without ever actually sitting down to study.
Mixing and matching study habits can be advantageous too. For example, I like to do lessons on Tsurukame on my phone because I like having the reading and meaning on the same screen instead of split into different pages the way the browser does. But I like having my laptop keyboard for reviews (faster than typing on the phone), so I usually do them either at home while sitting comfortably in bed and with no distractions, or waiting for my kid’s classes and activities to finish. These are loud, but no one’s talking directly to me so I put in my ear buds and tune out the world. However, I’ll also frequently pull out my phone in quiet moments and toss out a few reviews here and there throughout the day. I can’t do my reading practice while out and about though, it takes more focus than flashcards, so that’s limited to low distraction environments, while WK can be done in any small moment when using the back to back options (meaning and reading right after each other, rather than mix in with other words).