How do I get rid of a mental barrier with respect to continuing research work that I have already done?

This feeling is the worst. Ways I've found to alleviate it:

• If possible, get into some kind of collaborative rhythm with someone. Having a meeting or a short-term deadline can be a really good motivator for just getting yourself over that initial hump of icky feelings about your work.

• Along the same lines: Instead of thinking "where am I in this mess, and what come next?" it's sometimes better to think, "How can I explain what I've done so far to someone else?" Again, meeting regularly with others helps. You can also accomplish this by writing up some slides as if you are presenting what you've already done for a future seminar. They will probably come in handy, and it can get you back in touch with why you liked the problem in the first place. The next steps usually come naturally when you're familiar with the details of the problem again.

• brute force method: set a 20 minute timer and force yourself to work for 20 minutes, then take a 10 minute break. Adjust the time you commit to working down as much as you need to. I keep the 10 minute break constant, as I've found longer makes me feel like I'm starting over at the bottom of the motivation hill, and shorter isn't enough of a break to look forward to. This can be highly inefficient but sometimes it's the only way to get started. For me, once I'm in the groove I typically start snoozing the timer because I don't want to stop working.

• Longer term solutions: working through your feelings of shame around your work. There are some free resources online for this: journaling prompts or meditation exercises. The point is to get used to acknowledging awful feelings like fear or shame calmly without feeling panic, and over time you decondition your anxiety. This is supposed to help with avoidance behavior, though I haven't found immediate success here. If it works, it takes a lot of practice.

A simple tip that I use: keep a log with quite detailed notes of what you are doing and why you are doing it this way. I often found that the obstacle to continue on some previous work is to recover the train of thought which led me there, and leaving indications for my future self is very useful for this. It also has other advantages: obviously I'm prepared to explain my work from the notes, and sometimes it helps me realize in retrospect directions that I overlooked for example.

I personally use TiddlyWiki for my notes but of course that's matter of personal preference, a good old physical notebook can be just fine.