Personally, I just put in more effort. You can also be strategic about your time (cutting commute, meal prepping, etc). Time is money...eliminate everything thats monotonous. Make less mess at home, structure your routine, etc.
If you want it bad enough, you'll find a way. I've easily clocked in 20-30+ hours a week learning a different language, attaining certifications, etc while working full time. I'm still able to get my workout in every morning. I just don't waste my time with watching T.V., scrolling through facebook, etc. I know what's important to me. You'd be suprised how much time people waste on screens.
If you have to FORCE yourself to do it, you're not interesting in what your learning enough. Don't waste your time imo. Been there...you'll quit in a matter of months.
In terms if language learning, make friends who have the same language goals. Have a partner help you with the targeted language. I really don't believe in being tired. If your physically exhasted, change your job, etc.
Reflect, rebalance your priorities, eliminate everything that's unnecessary in your life.