There's a ton of exercises online--pull ups, TRX, dumbbells, campus board, etc.--but pulling them together is the crux of keeping up with a training regimen when you're injured.
Framework: Running Bucket List
Create a Google Sheets or equivalent list of every exercise, noting what muscle group it targets in a separate column. Before you hit the gym, determine what muscle group(s) you want to target and select exercises from your uber-list.
Having this full list written is key. The last thing you want to do is think about what exercises to do after a long day at work.
Keep Tally: FitNotes App
I've searched high and low for a good workout compiler/tracker app. This is by far the simplest and most practical. You can set up your routines and track weights/sets/time/etc.
Work out based on heartrate, not time
Endurance isn't my strength, so I couldn't actually complete HIIT workouts I found. Instead of doing prescribed "30 sec on, 10 sec rest" type workouts, I now base all my workouts on heartrate instead. I survive a workout and I can see small improvements in recovery time or max HR, which is more motivating week over week.
Do the "work" and let your heartrate go, but don't start another set until it's back down into the 150's. After a little bit, you'll know your range and can figure it out without the monitor.
Change it up...take yoga or something
Reality is that life will get to you, motivation will wane, you'll get bored. Substitute a workout for something totally different with no guilt.
I won't pay $200 for TRX-branded suspension trainers. This $40 version is made on 10mm rope with a pulley. You have to stabilize both sides of your body. It's a climbers' training dream! And the price is right.