What I would do first is to make your lifting and diet your new life. You have found reasons to deny yourself the pleasures of lifting for months at a time, so how about this:
Lift consistently for a period of time, say 8-12 months, 4-6 days per week, no excuses, just lift and get bigger and stronger. If you miss a workout it's not the end of the world, but get back in the gym and work.
Eat consistently well for the same period of time, clean real food in the proper amounts for gaining weight. Get in the habit of eating fewer cheat meals as you go along. You are going to make mistakes along the way, but learn from them and move on, always keeping your eyes on where you want to be, not where you are.
Take a multi-vitamin.
Drink one whey shake after your workout, since you already have it.
If you cannot stick to working out and eating, any supplements you buy now will be a total waste of money, will age and take up space in your kitchen or pantry, and remind you that you shouldn't have spent your money on them.
Once you have made this lifestyle a habit, once you have decided to continue on and that nothing will stop you from making the gains that you deserve, once you determine that 180 lbs sucks and you should be 45 lbs heavier so that when you walk through a door you have to walk through sideways to get your shoulders through, you will be ready for some supplements.
See ya in 8 months. Maybe.