One step at a time. Slow things down. Use a metronome. Also set yourself a schedule for your practice times. XXmins Alt Picking practice XXmins Sweep picking practice XXmins vice versa And stick with it. You may also need to allow for more time in some areas that need attention. Stay flexible (sounds sorta contradictory given I just talked about schedules..but you get the idea).
I think TIMEwaveXERO said it perfectly, practice is totally key with any instrument. It may seem tedious, but it will help in the long run and make you a better, well rounded player. I would also start by playing easy stuff with a met and build up speed.