Getting back from a layoff is easier than starting out as a complete beginner. One of the reasons for that is that you've learned the motor patterns before and had achieved the neurological adaptations that must precede muscle hypertrophy. Strength increase will actually occur before muscle growth starts, and the other way around, a decrease in strength will begin before muscle mass is lost.
Your previous training (assuming you had done it for a non-trivial amount of time) has incurred some long-lasting changes in your physiology. With slightly less than two months out of the gym, these are still very much applicable. However, some muscle mass has probably been lost (how much depends in part on your protein consumption in the meantime) as has the capacity of your body in recruiting all motor units on a movement for maximum efficiency.
So this means that
- you're not as strong as you were when you stopped,
- but some work capacity remains and you'll see a much faster catch-up to your previous level than when you had to initially build up to it.
Now, this is a double-edged sword. On the one hand it means that you can pick up your old routine, with lower weight on every exercise, and catch up within a matter of weeks. On the other hand, the efficient motor patterns you've developed along with some of the longer-lasting neurological and muscular adaptations can make it possible for you to lift weight in the gym, seemingly within your range, that exceeds your current capacity for recovery. And that can lead to a rather spectacular case of DOMS. Remember how sore you could be from a workout when you just started? Imagine that, only with the possibility of lifting much, much heavier weight.
So, do a solid deload. Make sure that the weight feels somewhat challenging but not too heavy. Every set should leave you feeling like you had several reps left in you, and after the last set you should feel like you could have done more. Just keep it at that and apply linear progression from workout to workout until you're at your previous level.
In short: you were best adapted for your old routines so those will serve you best. But you need to reduce the weight.