1984 Other Subaru Models

Transmission problem
1984 Other Subaru Models 4 cyl Four Wheel Drive Manual

Howdy. So heres the deal:
I wasn't being very smart and decided to drive my '84 "around town car" out way to far to go fishing. At about mile 55 and several steep up and downs through a canyon later I notice more smoke than the regular exhaust behind me. The engine was running fine so I pulled over checked the oil and fluids (were good) turned engine off to let cool for a bit. Starting back up she wouldn't pick up hardly at all and I couldn't get up to a speed greater than 45mph in any gear, so I pulled over again, turned off and let sit again. After starting the engine up again and putting in 1st she wouldn't move, just a very slight pull forward then settled in place. It was the same in reverse, very slight pull without moving the car and stop in place. So we towed it back to our house, I decided it was the clutch (I could be wrong) with some help from my friends and my own experience. After sitting almost a month in the garage (starting the engine a few times to keep it fresh) while I procrastinated replacing the clutch I went out to start the engine and thought maybe I'll just see what it does now when I put'er in gear. To my shock the transmission engaged and I was able to drive around the block. But I couldn't get over 15 mph this time in any gear. The engine still runs very solid and is well taken care of. I still think it is the clutch that has been giving me these troubles, but I thought it was really strange how she started driving again after sitting. I wanted to get some advice before I did replace the clutch in case there may be something else happening. Thanks in advance! Please let me know if there is any other info that would help or questions I can answer for you.