Playing with your hormones can cause emotional changes for a lot of people and it may be best to just not use them. Sarms are non-hormonal and might be a better alternative
I don't try for 1rm more than 2 or 3 times a year. You need to be properly rested in the days before and properly warmed up as well. You should reasonable know what your limit is roughly at judging from your normal routine as well.