It's good that you know about how many calories are necessary to maintain your weight. StrongLifts and Starting Strength have the same basic principles behind the program:
- Get strong as fast as possible
- Train whole body with major compound lifts
- Minimal assistance exercise
- Rest days are required between training sessions.
These are hard on your body. In order to keep increasing the amount you can lift, your body will need to use increasing amounts of energy. A common suggestion with these programs is to eat to support the program. Meaning try to out-eat a stall. That only works for so long.
You can use the pictures in Leigh Peele's blog for visually estimating body fat. Above 30% body fat, it's pretty useless to guess by site. Visual estimation is about as accurate as most other common forms of BF testing.
The bottom line is that the more you cut, the more your body will have problems trying to adapt and get stronger. 1800 Calories is the absolute minimum I would recommend you trying to eat in a day, and that only on rest days. I would recommend 2000 or 2100 on training days.
If you try to get most of your Calories in protein form, you will do better trying to lose fat. Do have carbs after you train, but don't overdo them and keep them low on rest days.
Consider adding HIIT to help speed up fat loss. High Intensity Interval Training such as Tabata style sprints, or other body weight exercise will also help. Just don't try to over achieve. Too much of this will affect your lifts.
I gained weight, but lost fat while doing StrongLifts and Starting Strength (consecutively). This lasted for a good while, but 5x5 was a bit much on squats when I got to where you are now. I switched to Starting Strength (which is 3x5, and swaps power cleans for barbell rows) about that time. This helped me push myself for another couple months. I managed to get to 310 lb squats before I had to switch to a weekly progression program.
The suggestions above coincide with what I did at that time. Resist the urge to do a deep cut--particularly while lifting heavy. Only cut enough calories till you see the results you are after.